When working with Telegram messenger, the users sometimes receive notifications which are indicative of some particular problem. Telegram errors may be different in nature and structure, understanding of which usually allows rapidly finding a way out of existing situation and continue working with an application.
A service notification may include the following parameters:
A code contains information on the problem’s category. For example, incorrect data processing while working with API is characterized by code 303, internal problems by 400, 401, 403 and server’s bugs by 500.
It means short designation of a problem in the form of alphanumeric symbols. For example, USERS_TOO_MUCH (the maximum number of users is exceeded).
This parameter includes detailed information and problem-solving techniques which allow rapidly eliminating it. The structure of Telegram errors does not involve obligatory usage of all three parameters. Notifications often include a code and an error type (for developers working with API) and a short description allowing even an uninformed person to understand a reason and find a way out of a non-standard situation (for common users).
Internal errors may be connected with incorrect authorization or improper use of application functionality. Here are several examples:
FIRSTNAME_INVALID: invalid user name;
LASTNAME_INVALID: invalid last name;
PHONE_NUMBER_INVALID: invalid phone number;
PHONE_NUMBER_OCCUPIED: telephone number is already used;
PHONE_CODE_EXPIRED: validation phone code is expired;
USERS_TOO_FEW: insufficient number of users;
USERS_TOO_MUCH: maximum limit of users is exceeded (for example, in a group chat); PHOTO_INVALID_DIMENSIONS: photo has invalid dimensions; AUTH_KEY_UNREGISTERED: authorization key is unregistered; AUTH_KEY_INVALID: invalid authorization key;
USER_DEACTIVATED: contact is deleted or in the process of deactivation;
SESSION_REVOKED: authorization is revoked, because one of the users has completed all sessions;
SESSION_EXPIRED: session is expired.
In Telegram messenger, one of the most wide-spread phenomena is a ban on sending messages to the users which are not in a contact list. At attempt of sending a message, the text notification «Sorry, you can only send messages to mutual contacts at the moment» is appeared. The given limitation is imposed by administrators, in case if clients complain of obtrusiveness or spam from some account.
External problems connected with the server’s work are the result of technical bugs occurring when the client’s request cannot be processed due to lack of access to a database or specific files. In this case, a user gets one of the following notifications:
For a period of Telegram existence, serious cases of Pavel Durovʼs messenger crash have not almost happened. In fact, there were only three of them:
The night of February 22nd to 23rd became a period of good and bad luck at the same time for Telegram. As a result of WhatsApp crash for practically three hours, lots of people started installing Pavel Durovʼs messenger on their smartphones. Login speed was equal to 100 accounts per second which resulted in server overload and temporary bugs.
On October 3, many Telegram users from all over the globe were tweeting about impossibility of connecting to the application or sending a message. After a while, the mobile version stopped being kept updated at all. According to some supposition, the given bug was provoked by a DDoS attack.
On August 5, Telegram clients from Russia, Germany and some other European countries reported about partial application unavailability. Although afterwards Telegram tech support did not give notice of any large-scale bugs.