Preferred Userscript Manager is Tampermonkey

[JustinS83]

@Challenger3802

Well Tampermonkey was the go-to choice for Firefox users, until Firefox updated everything and broke all the script hosting.

“Starting in Firefox version 57, only extensions built using WebExtensions APIs will work.”

“If a signed version is not available, contact the add-on developer or vendor to see if they can offer an updated and signed version of that add-on. You can also ask them to get their add-on signed.”

I just hope the developers find and fix this problem

I run Tampermonkey in Firefox 66.0.3 with no issue.