More accurately: I enable the addons and it's fine until I use the Browser in the other OS.

You shouldn't share profiles because there are links to files in files like extensions.json.

Best would be to use Sync to synchronize your profiles.

Ugh, sync, I hate it. When it it supposed to sync it doesn't do anything and another time it adds existing stuff a second time. I mean how does it even know in which direction I want to sync? Can't it just ask? I know you're probably not the person to address, but...

Anyway, thanks for pointing out the issue with the paths. That's the reason the addons are re-installed each time.

Well since Firefox sync is a pile of dog excrement I figured out a working solution:

I use a shared profile and run this script on each windows startup and a respective linux variant on Ubuntu startup:

D: cd \AppData\Waterfox\q4805j1x.shared

IF EXIST backup_win\extensions.json (

move extensions.json backup_linux move addonStartup.json.lz4 backup_linux move extension-settings.json backup_linux

move backup_win\extensions.json %cd% move backup_win\addonStartup.json.lz4 %cd% move backup_win\extension-settings.json %cd% )