Hello,
Im not sure If this is the right place however I know it will help a fair few people. I have found a fix for the above bug (or at least it fixed it for me).
Basically the bug is not a bug at all, its Norton up to its old tricks (or your own antivirus). I went onto Norton and restored a file it quarantined called something like 'csharp assembly'. Basically restore this back to its original place and make it a rule that Norton (or your antivirus) excludes this file on future scan and badabing badaboom you got yourself a working PRO Client.
Hope this helps and apologies to the moderators if this is in the wrong place.
:Grin: