When I add some add-ones for firefox, they always show installation failure. Such as Full Web Page Screenshot , Video DownloadHelper and etc. I want to know whether because they can only be added on firefox desktop? However, I use another browser based on firefox kernel they can be added in and can run normally.
Are you using Adguard app that creates the local VPN to block ads in apps?
There is a bug that breaks addons installation if you use Adguard app (not addon).
To fix that you need to disable the Adguard, then open Firefox settings / Delete browsing data and check “Cached images and files”, other things leave unchecked.
Then you can install addons again.
It can’t be solved by this way, and I don’t use adguard app. Thank you still!
Thanks. Maybe some addons need to be compatible with Android after.