Hello, Last week, when I started Firefox, it suddenly ran the Add-on Compatibility Check. After that, the interface was very different and I discovered that at least four of my add-ons had disappeared. They had not been disabled, as you would expect, but they had vanished from the hard drive. I wonder why the compatibility messes with my hard disk instead of only changing the configuration of Firefox by disabling the add-ons or removing them from the list with installed add-ons. Doing this with asking my permission is also not very polite. Note that I use (at my own risk) an older version of Firefox because I dislike the constant changes in the program. Therefore I am sure that the add-ons (like Tab Mix Plus, Status 4ever and an adblocker) were in fact compatible with my version of Firefox. They worked very well before they were shovelled away. So it seems that the Compatibility Check removed them because they are not compatible with the newest Firefox version instead of checking them with the real version I have installed. Has any-one had the same experience? Best regards, Bram