My spellchecker add-on doesn't work on this site. That is not okay.
As I said in the title, the spellchecker add-on I use, LanguageTool, does not work on this site. I am not fine with that. What's the best way to get it working here? Any answers that amount to "you don't" are not acceptable.
Opaite Mbohovái (3)
Ah, yes. Workaround is explained here: Why are some add-ons not allowed on sites restricted by Mozilla?
That allow option in the section that says run on sites with restrictions, something like that sure seems the way to go. Why doesn't the the Add-ons Manager show that option for this extension? How can I get that option?
The other way, of disabling the protection entirely, from the Configuration Editor, seems a bit like removing a pimple with a shotgun, figuratively speaking. It'll be gone, alright, but that way of removing it might cause added problems.
Extensions do not work on Mozilla websites because content scripts are blocked on several restricted domains that have special permissions to access and modify personal data.