Add-on toolbar not displaying
When I right click on Toolbars, my add-on bar is ticked but does not display. It makes no difference whether it's ticked or unticked.
Alla svar (1)
If you go into the Customize mode, does the bar have at least one control on it?
Alt+v (opens classic View menu) > Toolbars > Customize
Occasionally the file that stores toolbar customizations and some other display-related preferences becomes corrupted. You could try renaming the file so that Firefox returns to its default toolbar settings.
Open your current Firefox settings (AKA Firefox profile) folder using
Help > Troubleshooting Information > Show Folder
Switch back to Firefox and Exit
Pause while Firefox finishes its cleanup, then rename localstore.rdf to something like localstore.old
Restart Firefox. Any improvement?