Are you sure this is GlobalUserPasswdVc fault? Have you tried to export just this register via Database Maintenance > Register export option and import to new version if it fails?
More explanation @Paul:
When the issue occurs, should see if restarting presence or lookup helps. If so - that is the issue and should be sorted. First need to ensure that that is the issue...
Hello!
You can mark it as closed as option. If document is connected with other documents you can not delete it so you will not be able to delete PO, as you will not be able to remove Goods receipt...