On the mobile server a user has changed the password in Active Directory, there are a continuous session requests almost 1000 in 1 hour that of course blocks your account in AD. Does somebody know anything about this? Thank you.

Which version of MoS are you using? In the tray manager there is “Surveillance server address..” menu option. If you are using older version of MoS, then you should have fields for user name and password. You may change the password from there.