From the Tugsoft website: "Mar 13, 2012 New UO patch info. EA has changed how patching happens so UOAssist does not work correctly with the new systems. For now you can work around this by running UO without UOAssist ( run UO.exe ) and get UO all patched up. Then you can run UOAssist again and you will get errors but UOAssist and UO should run. I'm working on a proper fix." EDIT: Additional info... Since the .exe files for will be changing (you can tell if they've been rewritten by checking the date on the file), people using Vista/Win7 may have to give Admin permission to the new .exe files. This goes for UOAssist, UO/CC, UO/EC and any mapping software that is changed in response to the recent patching changes. Just a thought.