Since upgrading to new Firefox i get Error messages in Firefox and Thunderbird whenever I open a new tab: Type Error: classes (cid) is undefined or Components (cid) is undefined. How can I fix this? It shows up constantly.
This "Type Error: classes (cid) is undefined" or this "Type Error: Components (cid) is undefined keeps popping up in a small pop up box every time I open a tab or switch from Thunderbird to Firefox to open a site,
This "Type Error: classes (cid) is undefined" or this "Type Error: Components (cid) is undefined keeps popping up in a small pop up box every time I open a tab or switch from Thunderbird to Firefox to open a site,
All Replies (1)
This issue can be caused by an extension that isn't working properly.
Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the extensions is causing the problem (switch to the DEFAULT theme: Firefox (Tools) > Add-ons > Appearance/Themes).
- Don't make any changes on the Safe mode start window.
- https://support.mozilla.com/kb/Safe+Mode
If it does work in Safe-mode then disable all extensions and then try to find which is causing it by enabling one at a time until the problem reappears.
- Use "Disable all add-ons" on the Safe mode start window to disable all extensions.
- Close and restart Firefox after each change via "File > Exit" (Mac: "Firefox > Quit"; Linux: "File > Quit")
In Firefox 4 you can use one of these to start in Safe mode:
- Help > Restart with Add-ons Disabled
- Hold down the Shift key while double clicking the Firefox desktop shortcut (Windows)