I clicked now 4 times on the hyperlink, but the module simply won't install. Doesn't FF support more than 1 language?

simply click here in app store activate and its activatet again in browser. just saw in addons that it was grayed out and deactivatet and in context menu no option to turn on again. went here on the store and where the install button on the page usually is stand activate. did that et voila. working again.

werkt niet het koppelt niet zoals in het verleden

It simply doesn't work, there's no two ways about it. You install it, but all spell checking is still in American English and the British English one doesn't appear as an option. Have tried installing it, uninstalling it etc... over a period of months or more than a year, so it's not a temporary thing.

Spellcheck is activated in the options menu, but doesn't work on any pages other than Google which does it's own spell check

This dictionary still doesn't work! Why are British people, and anyone wishing to use contemporary British English, subjected to using 'Carnegie simpleton' American spelling?