After removing "extensions.rdf" I was able to install an extension. After a restart of Firefox I got the same error again when trying to install another extension. So, for me this wasn't a permanent solution.
-- "installLocation has no properties" error in nsExtensionManager.js during install/update of extensions https://launchpad.net/bugs/65609 -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
