I have had a couple of AOs that just stop working

[Seafarer Waverider]

I have a couple of AOs that have stopped working.  One seamed to do it when SL sent an update.  The other occured today when my av got stuck in a sitting position and I used the "stop animating me" button.  How can I fix these when this happens?

[Rolig Loon]

An AO should not just stop working.  It yours does, you may have accidentally clicked an OFF switch.  Just touching a HUD can do that sometimes.  It's also possible that you are using some other scripted tool that is sending an OFF signal that interferes with your AO.  Unless it's a real low-quality AO (one that turns ON/OFF with a chat command like "/1 AO ON", for example), that's not likely, but you never know.  And of course the AO may be poorly designed or busted.

I assume that you have tried taking it off and reattaching it.  That will often reset an AO's script.  If you haven't done that, try it.  Also, check to be sure whether it has stopped working EVERYWHERE or just in one or two sims.  Most good AOs will run even in regions where the landowner has turned off scripts, but some older ones or poorly made ones will stall in a no-script zone.

The viewer update should not make a difference.  I suspect that it was a coincidence.  Still, one way to tell would be to try another viewer.  The Firestorm viewer has its own built-in AO, but you could try using yours anyway and just keep that one inactive.