Hello, I've remembered that you wanted to hear a solution of the problem. Here it is.
The main problem was: Error while connecting to server with user M.Martynov ErrorCode is:401 (I found in a debug file).
According this sk110882 problem has been resolved. The user had a password, which is written in russian letters. After changing the password to english characters it started to work properly.
Also I'd like to share, that there was another problem user without access to the capsule (he has Failed Log In).
The most weird thing is that he starts to work normally after enabling the CVPND debug according the sk99053.
I mean when you are changing the LogLevel in the $CVPNDIR/conf/httpd.conf file, the user has OK Log in and certainly a good green log.
Eventually, the TAC engineer said that the problem will be delivered to developers, because this behaviour is completely anomaly.
Do you have any ideas why is that working?