I don't know if Firefox fixed everything, but Adblock Plus is working again. It's the only add on I use.
If anyone still hasn't gotten their add ons back, I suggest you read what Sucker76 posted in post #11. Enable studies. It's in options, privacy & security. Scroll down to Data Collection and use. Check the box allowing FF to install and run studies. Once your add ons are working again, you can go back and uncheck it.