diff --git a/Telegram/SourceFiles/lang/lang_hardcoded.h b/Telegram/SourceFiles/lang/lang_hardcoded.h
index 2247e04412..1cfc93df7a 100644
--- a/Telegram/SourceFiles/lang/lang_hardcoded.h
+++ b/Telegram/SourceFiles/lang/lang_hardcoded.h
@@ -26,5 +26,9 @@ inline QString ClearPathFailed() {
 	return qsl("Clear failed :(");
 }
 
+inline QString ProxyConfigError() {
+	return qsl("The proxy you are using is not configured correctly and will be disabled. Please find another one.");
+}
+
 } // namespace Hard
 } // namespace Lang
diff --git a/Telegram/SourceFiles/messenger.cpp b/Telegram/SourceFiles/messenger.cpp
index 4610454175..cc4d9b5ec5 100644
--- a/Telegram/SourceFiles/messenger.cpp
+++ b/Telegram/SourceFiles/messenger.cpp
@@ -25,6 +25,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "lang/lang_file_parser.h"
 #include "lang/lang_translator.h"
 #include "lang/lang_cloud_manager.h"
+#include "lang/lang_hardcoded.h"
 #include "observer_peer.h"
 #include "storage/file_upload.h"
 #include "mainwidget.h"
@@ -44,6 +45,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "base/qthelp_url.h"
 #include "boxes/connection_box.h"
 #include "boxes/confirm_phone_box.h"
+#include "boxes/confirm_box.h"
 #include "boxes/share_box.h"
 
 namespace {
@@ -305,6 +307,14 @@ void Messenger::setCurrentProxy(
 	Global::RefConnectionTypeChanged().notify();
 }
 
+void Messenger::badMtprotoConfigurationError() {
+	if (Global::UseProxy() && !_badProxyDisableBox) {
+		_badProxyDisableBox = Ui::show(Box<InformBox>(
+			Lang::Hard::ProxyConfigError(),
+			[=] { setCurrentProxy(Global::SelectedProxy(), false); }));
+	}
+}
+
 void Messenger::setMtpMainDcId(MTP::DcId mainDcId) {
 	Expects(!_mtproto);
 
diff --git a/Telegram/SourceFiles/messenger.h b/Telegram/SourceFiles/messenger.h
index 51b749be35..3a92c44cf3 100644
--- a/Telegram/SourceFiles/messenger.h
+++ b/Telegram/SourceFiles/messenger.h
@@ -17,6 +17,7 @@ class MainWidget;
 class FileUploader;
 class Translator;
 class MediaView;
+class BoxContent;
 
 namespace Core {
 class Launcher;
@@ -99,6 +100,7 @@ public:
 		return _dcOptions.get();
 	}
 	void setCurrentProxy(const ProxyData &proxy, bool enabled);
+	void badMtprotoConfigurationError();
 
 	// Set from legacy storage.
 	void setMtpMainDcId(MTP::DcId mainDcId);
@@ -240,6 +242,7 @@ private:
 	std::unique_ptr<AuthSession> _authSession;
 	base::Observable<void> _authSessionChanged;
 	base::Observable<void> _passcodedChanged;
+	QPointer<BoxContent> _badProxyDisableBox;
 
 	std::unique_ptr<Media::Audio::Instance> _audio;
 	QImage _logo;
diff --git a/Telegram/SourceFiles/mtproto/connection.cpp b/Telegram/SourceFiles/mtproto/connection.cpp
index 38dfa64102..426d051adb 100644
--- a/Telegram/SourceFiles/mtproto/connection.cpp
+++ b/Telegram/SourceFiles/mtproto/connection.cpp
@@ -2983,6 +2983,11 @@ void ConnectionPrivate::onError(
 		qint32 errorCode) {
 	if (errorCode == -429) {
 		LOG(("Protocol Error: -429 flood code returned!"));
+	} else if (errorCode == -444) {
+		LOG(("Protocol Error: -444 bad dc_id code returned!"));
+		InvokeQueued(_instance, [instance = _instance] {
+			instance->badConfigurationError();
+		});
 	}
 	removeTestConnection(connection);
 
diff --git a/Telegram/SourceFiles/mtproto/mtp_instance.cpp b/Telegram/SourceFiles/mtproto/mtp_instance.cpp
index 3350ed075b..2a9065efb0 100644
--- a/Telegram/SourceFiles/mtproto/mtp_instance.cpp
+++ b/Telegram/SourceFiles/mtproto/mtp_instance.cpp
@@ -54,6 +54,7 @@ public:
 	void requestConfigIfOld();
 	void requestCDNConfig();
 	void setUserPhone(const QString &phone);
+	void badConfigurationError();
 
 	void restart();
 	void restart(ShiftedDcId shiftedDcId);
@@ -398,6 +399,12 @@ void Instance::Private::setUserPhone(const QString &phone) {
 	}
 }
 
+void Instance::Private::badConfigurationError() {
+	if (_mode == Mode::Normal) {
+		Messenger::Instance().badMtprotoConfigurationError();
+	}
+}
+
 void Instance::Private::requestConfigIfOld() {
 	const auto timeout = Global::BlockedMode()
 		? kConfigBecomesOldForBlockedIn
@@ -1484,6 +1491,10 @@ void Instance::setUserPhone(const QString &phone) {
 	_private->setUserPhone(phone);
 }
 
+void Instance::badConfigurationError() {
+	_private->badConfigurationError();
+}
+
 void Instance::requestConfigIfOld() {
 	_private->requestConfigIfOld();
 }
diff --git a/Telegram/SourceFiles/mtproto/mtp_instance.h b/Telegram/SourceFiles/mtproto/mtp_instance.h
index 7c53c086ef..5a67b1f8b0 100644
--- a/Telegram/SourceFiles/mtproto/mtp_instance.h
+++ b/Telegram/SourceFiles/mtproto/mtp_instance.h
@@ -140,6 +140,7 @@ public:
 	void requestConfigIfOld();
 	void requestCDNConfig();
 	void setUserPhone(const QString &phone);
+	void badConfigurationError();
 
 	~Instance();