Dropping connection to server after assign group


I have a problem on one of the TeamSpeak servers. After trying to assign some groups, some clients - I lose connection with the server (at the moment of assign the group, I can not perform any actions on TS, but I can hear the voice of others) after a few seconds I lose the connection, then after reconnecting the group at the client still has not changed . I tried to disable all plugins and styles. Client version 3.5.7 Beta.


Now the problem concerns more users on the server (apart from changing nicknames, also sending a message or editing a channel), I have already done everything - unfortunately nothing helps.