The code is happening within the .NET Framework, and as best I can tell there is nothing to fix in GSP. The best I can suggest is to try to learn more about the error:
* Does it still happen if you log out and log back in?
* Does it happen if you are an anonymous user?
* Does it happen for other accounts?
It is kind of a long shot, but you can try repairing the .NET Framework. You can also try deleting the contents of the aspnet_Profile table (but don't do this if you are using user albums).
Roger Martin
Creator and Lead Developer of Gallery Server Pro