Mar 27, 2016
A new UOAssist.dll has been posted and the updater service updated.  I hope this will take care of the problem some have reported where UOAssist was reporting errors about the server they were logging into.
Mar 18, 2016
A new version of UOAssist.dll has been post ( 1.22.8 ).  In macros you can now change 'use item' lines to 'use item type and color'.  This will make it so UOAssist can use strength and/or super nova potions correctly.  Other things that share 'models' but have different colors will also benefit from this change (like fish types...).

Also Mysticism spells will get the benefits from the 'Reveal hidden power words' feature.
Mar 1, 2016
So my hope that just allowing multiple instances to run would be enough just didn't pan out.  I got some reports from people that allowed me to reproduce the problem with a single account (multiple instances of UO) and made the changes needed to get that working so I hope it works for those with multiple accounts.

To try it you'll need to manually download this new UOAssist.dll and put it in your UOAssist directory.  If all goes well I'll post all of the changes on the updater for those that don't want to tackle the manual modifications in a couple of days/ or this weekend.

Test UOAssist.dll
Mar 1, 2016
Made changes so the new updater works on Windows XP.
You'll have to manually update by downloading UOAssist.exe again (use link in previous post).

Feb 28, 2016
A new version of UOAssist.exe is available for testing.  It will allow you to start multiple instances even though this is not a supported feature.

It also has a new UpdateAce version.  Changes made to it make it easier to host the updating offsite so when power is out for extended periods it shouldn't cause a disruption of service.

The new version is available here .
Nov 13, 2015
Fixed the long standing problem UOAssist had when you logged out and then back in without restarting UO.  No longer should you get the error about UOAssist not knowing what account is being used.