Users cannot login.
#/opt/quest/bin/vastool user checkaccess <username>
WARNING: Error 40 access users's login shell /bin/ksh.
If a user's shell cannot be executed, that user will not be able to gain access to a system.
In the case of the example above the ksh shell was not installed on the system and the user attribute in AD was set to /bin/ksh.
Make sure that the shell the user is set to use in AD is installed on the system and that the path is the same as is set for the user.