The problem arose where we are trying to restore the live production databases into a test environment
Historically DAX has had its own users when it was integrated to windows security model the windows user's SID (SID is a unique identifier for a user or a group in Windows) was used to act like a user.
SIDs are specific for a particular domain, i.e. domain admin accounts thus in two different domains the same user will have different SIDs.
The problem is that when the DAX database is moved from the production environment to a test environment it carries the SID of the production environment in the security tables which is different from a SID of an account that is being used in the test environment.
The solution is as below:
* find out the SID of the user you use to run a DAX client after DB migration
o you can use whoami tool shipped with Windows - just run whoami /user in a console and you'll see a long string like S-1-5-21-15052... next to your login;
o if you use WinXP or an earlier Windows version you'll have to install Windows XP Support Tools to get the tool and afair it has a slightly different command line params... you'll need to use /sid option instead of /user
* run a tool like Ms SQL Management Studio and connect to the restored DAX database
* navigate to the UserInfo table, open it in a grid and update the SID value for user "admin" with the one you've found out previously
* start DAX client - you should login as an admin now
