After expanding the session settings (this is the data sent to Telegram), all community members encountered an error:
Code:
ДействиеВход в аккаунт Ошибка RPCError 400:
CONNECTION_SYSTEM_LANG_CODE_EMPTY (caused by
InvokeWithLayerRequest)Screenshot of the error—
This is because session files now store the Telegram client’s language pack parameter (lang_pack). To resolve the error, do the following—
And then—
Everything is ready 
; the error has been fixed. Enjoy using it 