"Debugging and troubleshooting", "List of MyChat Client errors", "Error #0283".
 
Error

Error #0283: it is impossible to create a private user group, such name already exists ("XXX")

 

Error description

You are trying to create a personal group that is linked to a particular person, but this name already exists in the list of created groups. Notice that various names in the upper and lower case are considered the same ones. For example, "My group" and "my GROUP". The spaces at the beginning and end of the name are automatically cut.

 

Problem solution

Choose another group name to avoid duplicates, or delete the old group to create a new one, but written in another case. Or simply rename the old group.