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,
Additional System Details
Every time Firefox opened
This started when...
Upgraded to newest Firefox
- The QuickTime Plugin allows you to view a wide variety of multimedia content in Web pages. For more information, visit the QuickTime Web site.
- Adobe PDF Plug-In For Firefox and Netscape 10.0.1
- Shockwave Flash 10.2 r159
- My Web Search Plugin Stub for 32-bit Windows
- Google Updater pluginhttp://pack.google.com/
- Google Update
- DRM Store Netscape Plugin
- DRM Netscape Network Object
- Npdsplay dll
- User Agent: Mozilla/5.0 (Windows NT 6.0; WOW64; rv:2.0.1) Gecko/20100101 Firefox/4.0.1
This issue can be caused by an extension that isn't working properly.
Start Firefox in Troubleshoot Firefox issues using Safe 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.
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 Troubleshoot Firefox issues using 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 Troubleshoot Firefox issues using Safe Mode:
- Help > Restart with Add-ons Disabled
- Hold down the Shift key while double clicking the Firefox desktop shortcut (Windows)