if there isn't a forced patch, you can continue to play without having to patch. Either change your shortcuts from uo.exe to client.exe, or go to the UO folder under program files and click on client.exe
If it is a forced patch, well, you're SOL. Have to wait until easyuo patches. If it's not forced and you somehow manage to patch, you can continue to use easyuo if you can find the previous client version. Rename it to something else, place it in the uo folder and open it.
Old clients wont work, since the last patch converted mul files to uop. So it has to be recent.