When I apply hotfix 4 to Pharos 7.2 I receive the error
006~ASP 0178~Server.CreateObject Access Error~The call to Server.CreateObject failed while checking permissions. Access is denied to this object.
In the directions on how to apply this hotfix it states to stop the www service and copy the PSDomain.dll into the Pharos Bin folder overwriting the existing then restart the www service. Was the PSDomain.dll file moved? If moved it usually retains the permissions it had wherever it was stored before, which are not adequate for a webapp.
If no or in doubt, you should be able to view the permissions on the Pharos bin folder and use the advanced "Replace permission on all child objects" option to fix broken permissions.
Another possibility is that you need to re-register the PSDomain.dll file, but this is rare. If the permissions do not help, try the commandline "regsvr32 psdomain.dll" from the Pharos bin folder.