I assume that you do not see extension's buttons on the toolbar ? Are they still present in browser.uiCustomization.state in about:config assuming you had them pinned previously ? Did you only copy the main location in "AppData\Roaming" used personal data like bookmarks and logins or also the secondary location in "AppData\Local" used for temporary files like the disk cache ? You can try to disable and re-enable an extension to see if that brings it back in the Extensions button drop-down. You can try "Clear the startup cache..." via the "Help -> More Troubleshooting Information" (about:support) page. *https://support.mozilla.org/en-US/kb/use-troubleshooting-information-page-fix-firefox You can also try to rename/remove compatibility.ini to force a reinitialize of the profile.