diff --git a/Telegram/SourceFiles/chat_helpers/emoji_keywords.cpp b/Telegram/SourceFiles/chat_helpers/emoji_keywords.cpp
index a878cada2..4878b7a09 100644
--- a/Telegram/SourceFiles/chat_helpers/emoji_keywords.cpp
+++ b/Telegram/SourceFiles/chat_helpers/emoji_keywords.cpp
@@ -557,7 +557,7 @@ void EmojiKeywords::refresh() {
 }
 
 std::vector<QString> EmojiKeywords::languages() {
-	if (!Main::Session::Exists()) {
+	if (!_api) {
 		return {};
 	}
 	refreshInputLanguages();
diff --git a/Telegram/SourceFiles/core/application.cpp b/Telegram/SourceFiles/core/application.cpp
index 606d73d39..ad4eb2bfc 100644
--- a/Telegram/SourceFiles/core/application.cpp
+++ b/Telegram/SourceFiles/core/application.cpp
@@ -120,9 +120,7 @@ Application::Application(not_null<Launcher*> launcher)
 			_mediaView->clearData();
 		}
 		if (session && !UpdaterDisabled()) {
-			if (const auto mtp = activeAccount().mtp()) {
-				UpdateChecker().setMtproto(mtp, session->userId());
-			}
+			UpdateChecker().setMtproto(session);
 		}
 	}, _lifetime);
 
@@ -580,6 +578,16 @@ bool Application::unreadBadgeMuted() const {
 		: false;
 }
 
+bool Application::offerLangPackSwitch() const {
+	// #TODO multi we offer only if we were upgraded from an old authed app.
+	return activeAccount().sessionExists();
+}
+
+bool Application::canApplyLangPackWithoutRestart() const {
+	// #TODO multi we can't if at least one account is authorized.
+	return !activeAccount().sessionExists();
+}
+
 void Application::setInternalLinkDomain(const QString &domain) const {
 	// This domain should start with 'http[s]://' and end with '/'.
 	// Like 'https://telegram.me/' or 'https://t.me/'.
diff --git a/Telegram/SourceFiles/core/application.h b/Telegram/SourceFiles/core/application.h
index f0733ab79..1f3c66531 100644
--- a/Telegram/SourceFiles/core/application.h
+++ b/Telegram/SourceFiles/core/application.h
@@ -85,23 +85,23 @@ public:
 	Application &operator=(const Application &other) = delete;
 	~Application();
 
-	not_null<Launcher*> launcher() const {
+	[[nodiscard]] not_null<Launcher*> launcher() const {
 		return _launcher;
 	}
 
 	void run();
 
-	Ui::Animations::Manager &animationManager() const {
+	[[nodiscard]] Ui::Animations::Manager &animationManager() const {
 		return *_animationsManager;
 	}
 
 	// Windows interface.
-	Window::Controller *activeWindow() const;
+	[[nodiscard]] Window::Controller *activeWindow() const;
 	bool closeActiveWindow();
 	bool minimizeActiveWindow();
-	QWidget *getFileDialogParent();
+	[[nodiscard]] QWidget *getFileDialogParent();
 	void notifyFileDialogShown(bool shown);
-	QWidget *getModalParent();
+	[[nodiscard]] QWidget *getModalParent();
 
 	// Media view interface.
 	void checkMediaViewActivation();
@@ -113,13 +113,13 @@ public:
 	void showTheme(
 		not_null<DocumentData*> document,
 		const Data::CloudTheme &cloud);
-	PeerData *ui_getPeerForMouseAction();
+	[[nodiscard]] PeerData *ui_getPeerForMouseAction();
 
-	QPoint getPointForCallPanelCenter() const;
-	QImage logo() const {
+	[[nodiscard]] QPoint getPointForCallPanelCenter() const;
+	[[nodiscard]] QImage logo() const {
 		return _logo;
 	}
-	QImage logoNoMargin() const {
+	[[nodiscard]] QImage logoNoMargin() const {
 		return _logoNoMargin;
 	}
 
@@ -129,7 +129,7 @@ public:
 	void saveSettingsDelayed(crl::time delay = kDefaultSaveDelay);
 
 	// Dc options and proxy.
-	not_null<MTP::DcOptions*> dcOptions() {
+	[[nodiscard]] not_null<MTP::DcOptions*> dcOptions() {
 		return _dcOptions.get();
 	}
 	struct ProxyChange {
@@ -155,28 +155,30 @@ public:
 
 	// Main::Session component.
 	[[nodiscard]] int unreadBadge() const;
-	bool unreadBadgeMuted() const;
+	[[nodiscard]] bool unreadBadgeMuted() const;
 
 	// Media component.
-	Media::Audio::Instance &audio() {
+	[[nodiscard]] Media::Audio::Instance &audio() {
 		return *_audio;
 	}
 
 	// Langpack and emoji keywords.
-	Lang::Instance &langpack() {
+	[[nodiscard]] Lang::Instance &langpack() {
 		return *_langpack;
 	}
-	Lang::CloudManager *langCloudManager() {
+	[[nodiscard]] Lang::CloudManager *langCloudManager() {
 		return _langCloudManager.get();
 	}
-	ChatHelpers::EmojiKeywords &emojiKeywords() {
+	[[nodiscard]] bool offerLangPackSwitch() const;
+	[[nodiscard]] bool canApplyLangPackWithoutRestart() const;
+	[[nodiscard]] ChatHelpers::EmojiKeywords &emojiKeywords() {
 		return *_emojiKeywords;
 	}
 
 	// Internal links.
 	void setInternalLinkDomain(const QString &domain) const;
-	QString createInternalLink(const QString &query) const;
-	QString createInternalLinkFull(const QString &query) const;
+	[[nodiscard]] QString createInternalLink(const QString &query) const;
+	[[nodiscard]] QString createInternalLinkFull(const QString &query) const;
 	void checkStartUrl();
 	bool openLocalUrl(const QString &url, QVariant context);
 	bool openInternalUrl(const QString &url, QVariant context);
diff --git a/Telegram/SourceFiles/core/update_checker.cpp b/Telegram/SourceFiles/core/update_checker.cpp
index 05f44f481..295a3ebb5 100644
--- a/Telegram/SourceFiles/core/update_checker.cpp
+++ b/Telegram/SourceFiles/core/update_checker.cpp
@@ -16,6 +16,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "core/click_handler_types.h"
 #include "mainwindow.h"
 #include "main/main_account.h"
+#include "main/main_session.h"
 #include "info/info_memento.h"
 #include "info/settings/info_settings_widget.h"
 #include "window/window_session_controller.h"
@@ -172,7 +173,7 @@ private:
 
 class MtpChecker : public Checker {
 public:
-	MtpChecker(QPointer<MTP::Instance> instance, int32 userId, bool testing);
+	MtpChecker(base::weak_ptr<Main::Session> session, bool testing);
 
 	void start() override;
 
@@ -879,16 +880,14 @@ void HttpLoaderActor::partFailed(QNetworkReply::NetworkError e) {
 }
 
 MtpChecker::MtpChecker(
-	QPointer<MTP::Instance> instance,
-	int32 userId,
+	base::weak_ptr<Main::Session> session,
 	bool testing)
 : Checker(testing)
-, _mtp(instance)
-, _mtpUserId(userId) {
+, _mtp(session) {
 }
 
 void MtpChecker::start() {
-	if (!_mtp.valid() || !_mtpUserId) {
+	if (!_mtp.valid()) {
 		LOG(("Update Info: MTP is unavailable."));
 		crl::on_main(this, [=] { fail(); });
 		return;
@@ -896,7 +895,7 @@ void MtpChecker::start() {
 	const auto updaterVersion = Platform::AutoUpdateVersion();
 	const auto feed = "tdhbcfeed"
 		+ (updaterVersion > 1 ? QString::number(updaterVersion) : QString());
-	MTP::ResolveChannel(&_mtp, _mtpUserId, feed, [=](
+	MTP::ResolveChannel(&_mtp, feed, [=](
 			const MTPInputChannel &channel) {
 		_mtp.send(
 			MTPmessages_GetHistory(
@@ -931,12 +930,7 @@ void MtpChecker::gotMessage(const MTPmessages_Messages &result) {
 			fail();
 		}
 	};
-	MTP::StartDedicatedLoader(
-		&_mtp,
-		_mtpUserId,
-		*location,
-		UpdatesFolder(),
-		ready);
+	MTP::StartDedicatedLoader(&_mtp, *location, UpdatesFolder(), ready);
 }
 
 auto MtpChecker::parseMessage(const MTPmessages_Messages &result) const
@@ -1044,7 +1038,7 @@ public:
 	int already() const;
 	int size() const;
 
-	void setMtproto(const QPointer<MTP::Instance> &mtproto, int32 userId);
+	void setMtproto(base::weak_ptr<Main::Session> session);
 
 	~Updater();
 
@@ -1089,8 +1083,7 @@ private:
 	Implementation _mtpImplementation;
 	std::shared_ptr<Loader> _activeLoader;
 	bool _usingMtprotoLoader = (cAlphaVersion() != 0);
-	QPointer<MTP::Instance> _mtproto;
-	int32 _mtprotoUserId = 0;
+	base::weak_ptr<Main::Session> _session;
 
 	rpl::lifetime _lifetime;
 
@@ -1238,7 +1231,7 @@ void Updater::start(bool forceWait) {
 			std::make_unique<HttpChecker>(_testing));
 		startImplementation(
 			&_mtpImplementation,
-			std::make_unique<MtpChecker>(_mtproto, _mtprotoUserId, _testing));
+			std::make_unique<MtpChecker>(_session, _testing));
 
 		_checking.fire({});
 	} else {
@@ -1301,11 +1294,8 @@ void Updater::test() {
 	start(false);
 }
 
-void Updater::setMtproto(
-		const QPointer<MTP::Instance> &mtproto,
-		int32 userId) {
-	_mtproto = mtproto;
-	_mtprotoUserId = userId;
+void Updater::setMtproto(base::weak_ptr<Main::Session> session) {
+	_session = session;
 }
 
 void Updater::handleTimeout() {
@@ -1405,9 +1395,7 @@ UpdateChecker::UpdateChecker()
 	if (IsAppLaunched()) {
 		const auto &account = Core::App().activeAccount();
 		if (account.sessionExists()) {
-			if (const auto mtproto = account.mtp()) {
-				_updater->setMtproto(mtproto, account.session().userId());
-			}
+			_updater->setMtproto(&account.session());
 		}
 	}
 }
@@ -1441,10 +1429,8 @@ void UpdateChecker::test() {
 	_updater->test();
 }
 
-void UpdateChecker::setMtproto(
-		const QPointer<MTP::Instance> &mtproto,
-		int32 userId) {
-	_updater->setMtproto(mtproto, userId);
+void UpdateChecker::setMtproto(base::weak_ptr<Main::Session> session) {
+	_updater->setMtproto(session);
 }
 
 void UpdateChecker::stop() {
diff --git a/Telegram/SourceFiles/core/update_checker.h b/Telegram/SourceFiles/core/update_checker.h
index 485db1e8d..4e32c3000 100644
--- a/Telegram/SourceFiles/core/update_checker.h
+++ b/Telegram/SourceFiles/core/update_checker.h
@@ -9,9 +9,9 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 
 #include "mtproto/dedicated_file_loader.h"
 
-namespace MTP {
-class Instance;
-} // namespace MTP
+namespace Main {
+class Session;
+} // namespace Main
 
 namespace Core {
 
@@ -41,7 +41,7 @@ public:
 	void stop();
 	void test();
 
-	void setMtproto(const QPointer<MTP::Instance> &mtproto, int32 userId);
+	void setMtproto(base::weak_ptr<Main::Session> session);
 
 	State state() const;
 	int already() const;
diff --git a/Telegram/SourceFiles/lang/lang_cloud_manager.cpp b/Telegram/SourceFiles/lang/lang_cloud_manager.cpp
index e081abe20..b332da7e2 100644
--- a/Telegram/SourceFiles/lang/lang_cloud_manager.cpp
+++ b/Telegram/SourceFiles/lang/lang_cloud_manager.cpp
@@ -249,7 +249,7 @@ void CloudManager::setSuggestedLanguage(const QString &langCode) {
 		_languageWasSuggested = true;
 		_firstLanguageSuggestion.notify();
 
-		if (Main::Session::Exists()
+		if (Core::App().offerLegacyLangPackSwitch()
 			&& _langpack.id().isEmpty()
 			&& !_suggestedLanguage.isEmpty()) {
 			_offerSwitchToId = _suggestedLanguage;
@@ -386,9 +386,7 @@ bool CloudManager::canApplyWithoutRestart(const QString &id) const {
 	if (id == qstr("#TEST_X") || id == qstr("#TEST_0")) {
 		return true;
 	}
-
-	// We don't support instant language switch if the auth session exists :(
-	return !Main::Session::Exists();
+	return Core::App().canApplyLangPackWithoutRestart();
 }
 
 void CloudManager::resetToDefault() {
diff --git a/Telegram/SourceFiles/main/main_account.cpp b/Telegram/SourceFiles/main/main_account.cpp
index 6149ae396..6f3002d84 100644
--- a/Telegram/SourceFiles/main/main_account.cpp
+++ b/Telegram/SourceFiles/main/main_account.cpp
@@ -126,12 +126,10 @@ void Account::createSession(
 	Expects(_sessionValue.current() == nullptr);
 
 	_session = std::make_unique<Session>(this, user, std::move(settings));
-
 	if (!serialized.isEmpty()) {
 		// For now it depends on Auth() which depends on _sessionValue.
-		local().readSelf(serialized, streamVersion);
+		local().readSelf(_session.get(), serialized, streamVersion);
 	}
-
 	_sessionValue = _session.get();
 }
 
@@ -154,13 +152,7 @@ bool Account::sessionExists() const {
 	return (_sessionValue.current() != nullptr);
 }
 
-Session &Account::session() {
-	Expects(sessionExists());
-
-	return *_sessionValue.current();
-}
-
-const Session &Account::session() const {
+Session &Account::session() const {
 	Expects(sessionExists());
 
 	return *_sessionValue.current();
diff --git a/Telegram/SourceFiles/main/main_account.h b/Telegram/SourceFiles/main/main_account.h
index 1ccde7510..2781f43aa 100644
--- a/Telegram/SourceFiles/main/main_account.h
+++ b/Telegram/SourceFiles/main/main_account.h
@@ -48,8 +48,7 @@ public:
 	}
 
 	[[nodiscard]] bool sessionExists() const;
-	[[nodiscard]] Session &session();
-	[[nodiscard]] const Session &session() const;
+	[[nodiscard]] Session &session() const;
 	[[nodiscard]] rpl::producer<Session*> sessionValue() const;
 	[[nodiscard]] rpl::producer<Session*> sessionChanges() const;
 
diff --git a/Telegram/SourceFiles/main/main_session.cpp b/Telegram/SourceFiles/main/main_session.cpp
index 47d7fe071..e2d1f39ca 100644
--- a/Telegram/SourceFiles/main/main_session.cpp
+++ b/Telegram/SourceFiles/main/main_session.cpp
@@ -117,11 +117,6 @@ Storage::Account &Session::local() const {
 	return _account->local();
 }
 
-bool Session::Exists() {
-	return Core::IsAppLaunched()
-		&& Core::App().activeAccount().sessionExists();
-}
-
 base::Observable<void> &Session::downloaderTaskFinished() {
 	return downloader().taskFinished();
 }
diff --git a/Telegram/SourceFiles/main/main_session.h b/Telegram/SourceFiles/main/main_session.h
index 0671d9330..6854b8075 100644
--- a/Telegram/SourceFiles/main/main_session.h
+++ b/Telegram/SourceFiles/main/main_session.h
@@ -71,8 +71,6 @@ public:
 	Session(const Session &other) = delete;
 	Session &operator=(const Session &other) = delete;
 
-	[[nodiscard]] static bool Exists();
-
 	[[nodiscard]] Main::Account &account() const;
 	[[nodiscard]] Storage::Account &local() const;
 
diff --git a/Telegram/SourceFiles/mtproto/dedicated_file_loader.cpp b/Telegram/SourceFiles/mtproto/dedicated_file_loader.cpp
index 3f43ac1d1..2a6e573d6 100644
--- a/Telegram/SourceFiles/mtproto/dedicated_file_loader.cpp
+++ b/Telegram/SourceFiles/mtproto/dedicated_file_loader.cpp
@@ -8,8 +8,8 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "mtproto/dedicated_file_loader.h"
 
 #include "mtproto/facade.h"
-#include "main/main_session.h"
 #include "main/main_account.h" // Account::sessionChanges.
+#include "main/main_session.h" // Session::account.
 #include "core/application.h"
 #include "base/call_delayed.h"
 
@@ -82,17 +82,19 @@ std::optional<DedicatedLoader::File> ParseFile(
 
 } // namespace
 
-WeakInstance::WeakInstance(QPointer<MTP::Instance> instance)
-: _instance(instance) {
+WeakInstance::WeakInstance(base::weak_ptr<Main::Session> session)
+: _session(session)
+, _instance(_session ? _session->account().mtp() : nullptr) {
 	if (!valid()) {
 		return;
 	}
 
 	connect(_instance, &QObject::destroyed, this, [=] {
 		_instance = nullptr;
+		_session = nullptr;
 		die();
 	});
-	Core::App().activeAccount().sessionChanges(
+	_session->account().sessionChanges(
 	) | rpl::filter([](Main::Session *session) {
 		return !session;
 	}) | rpl::start_with_next([=] {
@@ -100,19 +102,22 @@ WeakInstance::WeakInstance(QPointer<MTP::Instance> instance)
 	}, _lifetime);
 }
 
-bool WeakInstance::valid() const {
-	return (_instance != nullptr) && Main::Session::Exists();
+base::weak_ptr<Main::Session> WeakInstance::session() const {
+	return _session;
 }
 
-QPointer<MTP::Instance> WeakInstance::instance() const {
+bool WeakInstance::valid() const {
+	return (_session != nullptr);
+}
+
+Instance *WeakInstance::instance() const {
 	return _instance;
 }
 
 void WeakInstance::die() {
-	const auto instance = _instance.data();
 	for (const auto &[requestId, fail] : base::take(_requests)) {
-		if (instance) {
-			instance->cancel(requestId);
+		if (_instance) {
+			_instance->cancel(requestId);
 		}
 		fail(RPCError::Local(
 			"UNAVAILABLE",
@@ -138,9 +143,9 @@ void WeakInstance::reportUnavailable(
 }
 
 WeakInstance::~WeakInstance() {
-	if (const auto instance = _instance.data()) {
+	if (_instance) {
 		for (const auto &[requestId, fail] : base::take(_requests)) {
-			instance->cancel(requestId);
+			_instance->cancel(requestId);
 		}
 	}
 }
@@ -280,14 +285,14 @@ rpl::lifetime &AbstractDedicatedLoader::lifetime() {
 }
 
 DedicatedLoader::DedicatedLoader(
-	QPointer<MTP::Instance> instance,
+	base::weak_ptr<Main::Session> session,
 	const QString &folder,
 	const File &file)
 : AbstractDedicatedLoader(folder + '/' + file.name, kChunkSize)
 , _size(file.size)
 , _dcId(file.dcId)
 , _location(file.location)
-, _mtp(instance) {
+, _mtp(session) {
 	Expects(_size > 0);
 }
 
@@ -365,7 +370,6 @@ Fn<void(const RPCError &)> DedicatedLoader::failHandler() {
 
 void ResolveChannel(
 		not_null<MTP::WeakInstance*> mtp,
-		int32 userId,
 		const QString &username,
 		Fn<void(const MTPInputChannel &channel)> done,
 		Fn<void()> fail) {
@@ -374,20 +378,21 @@ void ResolveChannel(
 			).arg(username));
 		fail();
 	};
-	if (!userId) {
+	const auto session = mtp->session();
+	if (!mtp->valid()) {
 		failed();
 		return;
 	}
 
 	struct ResolveResult {
-		int32 userId = 0;
+		base::weak_ptr<Main::Session> session;
 		MTPInputChannel channel;
 	};
 	static std::map<QString, ResolveResult> ResolveCache;
 
 	const auto i = ResolveCache.find(username);
 	if (i != end(ResolveCache)) {
-		if (i->second.userId == userId) {
+		if (i->second.session.get() == session.get()) {
 			done(i->second.channel);
 			return;
 		}
@@ -400,7 +405,7 @@ void ResolveChannel(
 		if (const auto channel = ExtractChannel(result)) {
 			ResolveCache.emplace(
 				username,
-				ResolveResult { userId, *channel });
+				ResolveResult { session, *channel });
 			done(*channel);
 		} else {
 			failed();
@@ -430,7 +435,6 @@ std::optional<MTPMessage> GetMessagesElement(
 
 void StartDedicatedLoader(
 		not_null<MTP::WeakInstance*> mtp,
-		int32 userId,
 		const DedicatedLoader::Location &location,
 		const QString &folder,
 		Fn<void(std::unique_ptr<DedicatedLoader>)> ready) {
@@ -438,7 +442,7 @@ void StartDedicatedLoader(
 		const auto file = ParseFile(result);
 		ready(file
 			? std::make_unique<MTP::DedicatedLoader>(
-				mtp->instance(),
+				mtp->session(),
 				folder,
 				*file)
 			: nullptr);
@@ -450,7 +454,7 @@ void StartDedicatedLoader(
 	};
 
 	const auto [username, postId] = location;
-	ResolveChannel(mtp, userId, username, [=, postId = postId](
+	ResolveChannel(mtp, username, [=, postId = postId](
 			const MTPInputChannel &channel) {
 		mtp->send(
 			MTPchannels_GetMessages(
diff --git a/Telegram/SourceFiles/mtproto/dedicated_file_loader.h b/Telegram/SourceFiles/mtproto/dedicated_file_loader.h
index 949dfa6bc..0f57ebef5 100644
--- a/Telegram/SourceFiles/mtproto/dedicated_file_loader.h
+++ b/Telegram/SourceFiles/mtproto/dedicated_file_loader.h
@@ -9,11 +9,15 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 
 #include "mtproto/mtp_instance.h"
 
+namespace Main {
+class Session;
+} // namespace Main
+
 namespace MTP {
 
 class WeakInstance : private QObject, private base::Subscriber {
 public:
-	WeakInstance(QPointer<Instance> instance);
+	explicit WeakInstance(base::weak_ptr<Main::Session> session);
 
 	template <typename T>
 	void send(
@@ -22,8 +26,9 @@ public:
 		Fn<void(const RPCError &error)> fail,
 		ShiftedDcId dcId = 0);
 
-	bool valid() const;
-	QPointer<Instance> instance() const;
+	[[nodiscard]] base::weak_ptr<Main::Session> session() const;
+	[[nodiscard]] bool valid() const;
+	[[nodiscard]] Instance *instance() const;
 
 	~WeakInstance();
 
@@ -32,7 +37,8 @@ private:
 	bool removeRequest(mtpRequestId requestId);
 	void reportUnavailable(Fn<void(const RPCError &error)> callback);
 
-	QPointer<Instance> _instance;
+	base::weak_ptr<Main::Session> _session;
+	Instance *_instance = nullptr;
 	std::map<mtpRequestId, Fn<void(const RPCError &)>> _requests;
 	rpl::lifetime _lifetime;
 
@@ -115,7 +121,7 @@ public:
 	};
 
 	DedicatedLoader(
-		QPointer<Instance> instance,
+		base::weak_ptr<Main::Session> session,
 		const QString &folder,
 		const File &file);
 
@@ -143,7 +149,6 @@ private:
 
 void ResolveChannel(
 	not_null<MTP::WeakInstance*> mtp,
-	int32 userId,
 	const QString &username,
 	Fn<void(const MTPInputChannel &channel)> done,
 	Fn<void()> fail);
@@ -153,7 +158,6 @@ std::optional<MTPMessage> GetMessagesElement(
 
 void StartDedicatedLoader(
 	not_null<MTP::WeakInstance*> mtp,
-	int32 userId,
 	const DedicatedLoader::Location &location,
 	const QString &folder,
 	Fn<void(std::unique_ptr<DedicatedLoader>)> ready);
diff --git a/Telegram/SourceFiles/mtproto/mtp_instance.cpp b/Telegram/SourceFiles/mtproto/mtp_instance.cpp
index e2211c640..1e0c37976 100644
--- a/Telegram/SourceFiles/mtproto/mtp_instance.cpp
+++ b/Telegram/SourceFiles/mtproto/mtp_instance.cpp
@@ -16,7 +16,6 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "mtproto/sender.h"
 #include "storage/localstorage.h"
 #include "calls/calls_instance.h"
-#include "main/main_session.h" // Session::Exists.
 #include "main/main_account.h" // Account::configUpdated.
 #include "apiwrap.h"
 #include "core/application.h"
@@ -164,7 +163,6 @@ public:
 	[[nodiscard]] rpl::lifetime &lifetime();
 
 private:
-	bool hasAuthorization();
 	void importDone(const MTPauth_Authorization &result, mtpRequestId requestId);
 	bool importFail(const RPCError &error, mtpRequestId requestId);
 	void exportDone(const MTPauth_ExportedAuthorization &result, mtpRequestId requestId);
@@ -1106,10 +1104,6 @@ bool Instance::Private::rpcErrorOccured(mtpRequestId requestId, const RPCFailHan
 	return true;
 }
 
-bool Instance::Private::hasAuthorization() {
-	return Main::Session::Exists();
-}
-
 void Instance::Private::importDone(const MTPauth_Authorization &result, mtpRequestId requestId) {
 	const auto shiftedDcId = queryRequestByDc(requestId);
 	if (!shiftedDcId) {
@@ -1230,7 +1224,7 @@ bool Instance::Private::onErrorDefault(mtpRequestId requestId, const RPCError &e
 
 		DEBUG_LOG(("MTP Info: changing request %1 from dcWithShift%2 to dc%3").arg(requestId).arg(dcWithShift).arg(newdcWithShift));
 		if (dcWithShift < 0) { // newdc shift = 0
-			if (false && hasAuthorization() && _authExportRequests.find(requestId) == _authExportRequests.cend()) {
+			if (false/* && hasAuthorization() && _authExportRequests.find(requestId) == _authExportRequests.cend()*/) {
 				//
 				// migrate not supported at this moment
 				// this was not tested even once
@@ -1305,7 +1299,7 @@ bool Instance::Private::onErrorDefault(mtpRequestId requestId, const RPCError &e
 			LOG(("MTP Error: unauthorized request without dc info, requestId %1").arg(requestId));
 		}
 		auto newdc = BareDcId(qAbs(dcWithShift));
-		if (!newdc || newdc == mainDcId() || !hasAuthorization()) {
+		if (!newdc || newdc == mainDcId()) {
 			if (!badGuestDc && _globalHandler.onFail) {
 				(*_globalHandler.onFail)(requestId, error); // auth failed in main dc
 			}
diff --git a/Telegram/SourceFiles/settings/settings_codes.cpp b/Telegram/SourceFiles/settings/settings_codes.cpp
index e00b98c36..57a279eb6 100644
--- a/Telegram/SourceFiles/settings/settings_codes.cpp
+++ b/Telegram/SourceFiles/settings/settings_codes.cpp
@@ -163,18 +163,19 @@ auto GenerateCodes() {
 				return;
 			}
 
+			const auto weak = base::make_weak(&window->session());
 			FileDialog::GetOpenPath(Core::App().getFileDialogParent(), "Open audio file", audioFilters, crl::guard(&window->session(), [=](const FileDialog::OpenResult &result) {
-				if (Main::Session::Exists() && !result.paths.isEmpty()) {
+				if (weak && !result.paths.isEmpty()) {
 					auto track = Media::Audio::Current().createTrack();
 					track->fillFromFile(result.paths.front());
 					if (track->failed()) {
 						Ui::show(Box<InformBox>(
 							"Could not audio :( Errors in 'log.txt'."));
 					} else {
-						window->session().settings().setSoundOverride(
+						weak->settings().setSoundOverride(
 							key,
 							result.paths.front());
-						window->session().saveSettingsDelayed();
+						weak->saveSettingsDelayed();
 					}
 				}
 			}));
diff --git a/Telegram/SourceFiles/storage/serialize_common.cpp b/Telegram/SourceFiles/storage/serialize_common.cpp
index 9cd43a305..93f249ba8 100644
--- a/Telegram/SourceFiles/storage/serialize_common.cpp
+++ b/Telegram/SourceFiles/storage/serialize_common.cpp
@@ -216,7 +216,10 @@ PeerData *readPeer(
 		return nullptr;
 	}
 
-	const auto loaded = session->data().peerLoaded(peerId);
+	const auto selfId = session->userPeerId();
+	const auto loaded = (peerId == selfId)
+		? session->user().get()
+		: session->data().peerLoaded(peerId);
 	const auto result = loaded ? loaded : session->data().peer(peerId).get();
 	if (!loaded) {
 		result->loadedStatus = PeerData::FullLoaded;
@@ -237,7 +240,7 @@ PeerData *readPeer(
 		userpicAccessHash = access;
 
 		const auto showPhone = !user->isServiceUser()
-			&& (user->id != session->userPeerId())
+			&& (user->id != selfId)
 			&& (contact <= 0);
 		const auto pname = (showPhone && !phone.isEmpty())
 			? App::formatPhone(phone)
@@ -256,7 +259,7 @@ PeerData *readPeer(
 				user->botInfo->inlinePlaceholder = inlinePlaceholder;
 			}
 
-			if (user->id == session->userPeerId()) {
+			if (user->id == selfId) {
 				user->input = MTP_inputPeerSelf();
 				user->inputUser = MTP_inputUserSelf();
 			} else {
diff --git a/Telegram/SourceFiles/storage/storage_account.cpp b/Telegram/SourceFiles/storage/storage_account.cpp
index 5d11087f9..84295ff50 100644
--- a/Telegram/SourceFiles/storage/storage_account.cpp
+++ b/Telegram/SourceFiles/storage/storage_account.cpp
@@ -2444,14 +2444,17 @@ void Account::writeSelf() {
 	writeMapDelayed();
 }
 
-void Account::readSelf(const QByteArray &serialized, int32 streamVersion) {
+void Account::readSelf(
+		not_null<Main::Session*> session,
+		const QByteArray &serialized,
+		int32 streamVersion) {
 	QDataStream stream(serialized);
-	const auto user = _owner->session().user();
+	const auto user = session->user();
 	const auto wasLoadedStatus = std::exchange(
 		user->loadedStatus,
 		PeerData::NotLoaded);
 	const auto self = Serialize::readPeer(
-		&_owner->session(),
+		session,
 		streamVersion,
 		stream);
 	if (!self || !self->isSelf() || self != user) {
diff --git a/Telegram/SourceFiles/storage/storage_account.h b/Telegram/SourceFiles/storage/storage_account.h
index b07892021..25b40d665 100644
--- a/Telegram/SourceFiles/storage/storage_account.h
+++ b/Telegram/SourceFiles/storage/storage_account.h
@@ -120,7 +120,13 @@ public:
 	[[nodiscard]] Export::Settings readExportSettings();
 
 	void writeSelf();
-	void readSelf(const QByteArray &serialized, int32 streamVersion);
+
+	// Read self is special, it can't get session from account, because
+	// it is not really there yet - it is still being constructed.
+	void readSelf(
+		not_null<Main::Session*> session,
+		const QByteArray& serialized,
+		int32 streamVersion);
 
 	void markBotTrusted(not_null<UserData*> bot);
 	[[nodiscard]] bool isBotTrusted(not_null<UserData*> bot);
diff --git a/Telegram/SourceFiles/storage/storage_cloud_blob.cpp b/Telegram/SourceFiles/storage/storage_cloud_blob.cpp
index 83d0b5616..d037884c0 100644
--- a/Telegram/SourceFiles/storage/storage_cloud_blob.cpp
+++ b/Telegram/SourceFiles/storage/storage_cloud_blob.cpp
@@ -104,8 +104,7 @@ BlobLoader::BlobLoader(
 , _folder(folder)
 , _id(id)
 , _state(Loading{ 0, size })
-, _mtproto(session->account().mtp())
-, _mtprotoUserId(session->userId()) {
+, _mtproto(session.get()) {
 	const auto ready = [=](std::unique_ptr<MTP::DedicatedLoader> loader) {
 		if (loader) {
 			setImplementation(std::move(loader));
@@ -113,12 +112,7 @@ BlobLoader::BlobLoader(
 			fail();
 		}
 	};
-	MTP::StartDedicatedLoader(
-		&_mtproto,
-		_mtprotoUserId,
-		location,
-		_folder,
-		ready);
+	MTP::StartDedicatedLoader(&_mtproto, location, _folder, ready);
 }
 
 int BlobLoader::id() const {
diff --git a/Telegram/SourceFiles/storage/storage_cloud_blob.h b/Telegram/SourceFiles/storage/storage_cloud_blob.h
index 489bc8a72..d864307e9 100644
--- a/Telegram/SourceFiles/storage/storage_cloud_blob.h
+++ b/Telegram/SourceFiles/storage/storage_cloud_blob.h
@@ -107,7 +107,6 @@ private:
 	rpl::variable<BlobState> _state;
 
 	MTP::WeakInstance _mtproto;
-	int32 _mtprotoUserId = 0;
 
 	std::unique_ptr<MTP::DedicatedLoader> _implementation;