VJP
VJP
what java version are you running? have you tried 8u311 ? see https://github.com/simibubi/Above-and-Beyond/issues/363#issuecomment-1029693732
My guess is this https://github.com/simibubi/Above-and-Beyond/issues/363#issuecomment-1029693732 java version 8u311 is needed
I don't have a clue about Firefox Addons and js I just followed this [tutorial](https://developer.mozilla.org/en-US/Add-ons/SDK/Tutorials/Using_third-party_modules_%28jpm%29) on adding menu items.