I tried the recent white hole releases for each of the UXP browsers, and the addons are back!

But i do have a warning for anyone who feels like updating, please just don't.

And if you are brave enough to do it or crazy enough, once any announcement comes out for 0.4 testing...

GO BACK IMMEDIATELY!

Stuff will break after that. 

It probably better to be patient though in general. 

The only error I know of that still exists is on icedove-uxp and it involves feed accounts...

XML Parsing Error: undefined entity
Location: chrome://messenger-newsblog/content/feedAccountWizard.xul
Line Number 50, Column 3:  <wizardpage id="done"
--^

That is all!