When the current simulator runs, it modifies files in the Gaia profile, which is location inside the extension. Since it is now signed, this breaks the signature, which covers all files inside the extension. While WebIDE can still run the simulator (since it does not actually require simulator JS to be running), the user is left with a yellow / red warning bar in the add-on manager for each simulator they have used. One way to resolve this would be for WebIDE to first copy the Gaia profile out of the add-on directory and run it from there instead. However, that would not fixed the users already seeing issues... they would have to reset to a pristine copy first somehow.