multisim 12.0.1 database manager crashes

[User100]

I have Multisim 12.0.1 and have been using it for some time.  I recently attempted to open the database manager but the database manager would never launch and the mouse pointer shows my machine is still attempting to launch it.  I then have to force multisim to stop and then restart it.  once launched, I can place parts from the master db and the usr db, but I do not have any parts in the coporate db.

I received a clean corporate database some time ago from Tien, following a similar corruption event.  at that time it was my corporate database with a corruption.  so I attempted to diagnose / fix the problem as I describe next:

1) renamed my usr database and launching Multisim 12 it recreates a usr database so I then merged my renamed database.  No luck.  after this the database manager still crashed.

2) I then copied a clean corporate database into the corporate database directory.  No luck.  after this the database manager still crashed.

3)  I then grabbed a very old master database(previous version), renamed my master database (to preserve it) and attempted to use the very old master database.  I got an error message that the master database version was not compatible but I was able to launch the database manager and see both the corporate and usr databases.

  I was convinced this time it was the master database somehow corrupted; however......

4) since I have two seats for this version.  I was able to grab a master database from the other installtion, copy it to my "believed to be corrupted" machine.  launched the database manager but no luck... just locks with the perception of something working as the mouse poiniter is a rotating circle.  

any suggestions?

[User100]

recopied corporate data base with clean one.  problem resolved itself after restarting multisim.