I have two computers: One I let update from Microsoft automatically, one I ONLY update manually with specific security updates. The auto-updating one can no longer use Mobi2mobi GUI using Win32. Just like the others have said, it opens, you ask it to open a file and it hangs forever, eventually using 99% cpu while it just sits doing nothing.
Meanwhile on the other machine it still works great. Something Microsoft kicked out in the last round of updates broke this thing and it makes me so, so sad!