If your computer doesnt finish a live update, the next one returns an error LU1803. It can be fixed by searching for the hidden files that are found by searching for *SETTINGS*LIVEUPDATE, and deleting them. It took me a *long* time to figure it out the first time it happened, but this time I suspected that it happened again, and found it quickly.

I don't know where this could be put to keep it readily available, but it should be first and foremost the first thing to try.