Sytem menu not show for admin user

I had working server with ISPconfig 3.0.5.3.
But after I joined to this server another fresh installed server with ISPconfig, no more System menu shown in master server's panel.
All sites are working on master server, but only problem is with the System menu, because I can't manage servers anymore.
Both servers are ubuntu 12.04.4.
Can anyone have suggestions how to resolve this situation?