Not working on my Macbook

It worked on the same harddisk, on my older Macbook. Then, I transferred the HD to my new Macbook and now, although everything else works fine, LT doesn’t.
OS: High Sierra
Firefox: 72.0.1

Hi Mathias, can you explain what exactly doesn’t work? Do you see the “LT” icon in the toolbar? Does it work on our simple test page, LanguageTool browser add-on test?

So: yes, I see the icon. I also checked that LT was turned on. In fact, everything is on default settings.
I went to the test page and it doesn’t work either. All I see is the standard text correction tool’s underlining red dots.

Have you tried uninstalling and re-installing the add-on?

I have done that, of course.
Next thing I should do would probably be to delete its settings, if I can find them.

Have you checked if the LT-icon in the toolbar is not a ‘ghost’?

one of the macs at work had this issue with a network monitoring agent: the program-proper had been removed by a bogus (we learned later) cleanup tool, but the file that created the top-bar icon was still there and caused both installer and uninstaller to fail. (installer said “program already installed” while uninstaller said “no such program installed”)

The LT-tooltip is bright and shiny in my toolbar and all the switches in its menu are turned on.

doesn’t mean it can’t be a ‘ghost’.
Secondly, in the worst case, your issue may actually be a symptom of profile-corruption, which has only one cure… full profile reset.

I see. Okay, I’ll try this. Could indeed have happened due to the HD swap from one Macbook to the next. I just noticed the translation tool “Simple Translate” was also unresponsive.

One warning: resetting your profile should be done as a last resort as you’ll have to reinstall each and every add-on afterwards.