"Debugging and troubleshooting", "List of MyChat Client errors", "Error #0307".
 
Error

Error #0307: the list contains UIN = 0
 

Error description

In the command's user list that transferred on the server, has a UIN of the built-in bot, but it's not allowed to do this in the command.
 
Problem solution

If you work with MyChat via API or directly using an open network protocol, change the transferred data.