Extension icon don't show up after sync
After sync Firefox with my account, saved extensions are recovered successfull, but icons don't show up in toolbar. The only way I have refreshed and forced to show up was allowing the extension to execute in private window, doing a "refresh" of the extension and showing the image of the icon.
You can check for problems with the extensions registry files in the profile folder.
Try to to reset the extensions registry and rename extensions.json (extensionsOLD.json) and rename/remove previously used extensions files like extensions.ini and extensions.sqlite when present and rename/remove compatibility.ini in the Firefox profile folder with Firefox closed.
New files will be created when required.
See "corrupt extension files":
You can check for possible updates in case of issues.
- click the cogwheel button (left of the Search bar) on the about:addons page to "Check for updates"
You can use the button on the "Help -> Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page.
- Help -> Troubleshooting Information -> Profile Folder/Directory:
Windows: Open Folder; Linux: Open Directory; Mac: Show in Finder