Someone reported the icon does not appear in FIrefox 47.
After that I tried updating to FIrefox 47, yes the addon icon does not appear.
The addon now is WebExtension. I then tried to downgrade the addon to previous version which was made by addon SDK. The addon icon appears again.
After that I tried to reinstall the addon from the site(upgrade to the newest version), but when I press install I got this notification.
The add-on downloaded from this site could not be installed because it appears to be corrupt.
What’s wrong here? I haven’t tried downgrading Firefox but why it’s working fine in 46 but after upgrading to 47 it’s not working?
The fix for this bug will ship in Firefox 48. In the interim you should just avoid including unsupported manifest flags. The details are in this bug report.