"Debugging and troubleshooting", "List of MyChat Client errors", "Error #0274".
Error #0274: you haven't specified your work phone number
You do not have a work phone number in your profile.
This error occurs when some operation requires a work phone number. For example, for integration with Asterisk.
Open your profile in MyChat and specify your work phone number. You can also do it on Admin Panel, the section "Users", "Users list".