# Error notification
The functions described in this document can only be used by corporate users who have submitted the required applications. To use it with your LINE Official Account, contact your sales representative or contact our Sales partners (opens new window).
If the user adds your LINE Official Account as a friend or sends a message to your LINE Official Account, LINE platform sends a webhook event to the URL (bot server) specified in the LINE Developers Console "Webhook URL".
If the bot server returns an error in response to this webhook event, the channel administrator will receive a notification email informing them of the occurrence of the error. This option is called the "error notification" function.
# Notification email
For more information, see the information (for corporate users) on April 28, 2021, The subject of the email sent upon error notification will be changed.
This topic explains the email sent by the error notification function.
|Email recipients||An email is sent to the following email addresses.|
|Subject||Messaging API: Your server did not return [200 OK] - |
|Where to find error information||One of the following "Notification contents" is described. For more information on errors, check the "Errors" tab of the "Statics" page in the LINE Developers Console.|
# Notification contents
|could_not_connect - (Connection failed: ||The LINE Platform could not connect to the webhook URL. A bot server outage or communication failure might have occurred.|
|request_timeout - (Request timeout)||The bot server didn't return a response within a second. Bot server processing, such as replying to messages, might have slowed down.|
|error_status_code - ( ||The bot server returned a response whose status code was not 2xx.|
|unclassified||An error other than the above occurred.|