Platform 15.0.2 (May 17, 2018). Please donate.
400+ real apps, New: Falkon browser (Jun 04, 2018)
Over 980 million app downloads
Where could I get the last version of FF to get the add ons working again?
I would recommend switching to Firefox Portable ESR which will be at 52.x and receive security updates through April 2018. You can download it here: https://portableapps.com/apps/internet/firefox-portable-esr
The last stable branch version that supported legacy extensions was Firefox Portable 56.0.2. You may wish to temporarily reinstall that and sync to Mozilla before installing Firefox ESR 52.x as the profiles aren't quite compatible. Do not use Firefox 56 to go online on regular websites, though, as it has known security issues.
Sometimes, the impossible can become possible, if you're awesome!
Alright, thank you very much for the link.
I will do it like that.
Windows 10 Home, 64bit