Disabling the "OneClick YouTube Downloader 1.0.7" fixed it for me too. Tks "jseger9000"

cid refers to the user ID for conduit toolbar publishers. Somehow the latest update is not compatible with the Toolbars that are created by Conduit. Disable your toolbars and see if this message still appears.

FF 10 Update had a Microsoft.Net add-on/ plug-in compatibility issue. I was prompted to search for a newer .Net version... I think therein was the problem. I clicked YES. After the search found what was described as an upgrade to the extension of the .Net framework, I was prompted to WAIT while it installed. I waited for an HOUR (not my idea of time well spent). The upgrade animation was still spinning when I closed and loaded FF 10 and get the infernal error message every time I open a new window or session! I tried system restore and FF didn't even work from the previous restore point. Now my patience is tested with a bunch of error messages with each session or new page. Too much time on this already. Maybe uninstall and use Chrome. Never heard of safe mode. Loathe to waste more time on it. Uninstall or fix? That is the question.

I went to Add Remove Programs and uninstalled the Orbit Downloader and I am no longer receiving the TypeError: Components.classes[cid] is undefined message.

Disabling the "OneClick YouTube Downloader" fixed it for me too.

I solved this problem by deleting the file "{35379F86-8CCB-4724-AE33-4278DE266C70}" on the "extension" folder located at the backup folder of the history and bookmarks of mozilla.

Hi, I just switched to FF11 from 3.6 and now I'm getting the TypeError: Components.classes[cid] message every time FF starts up. I've tried some of the suggestions here, but even after turning off all my extensions, it still display the error message. It, however, works OK when in safe mode. Will appreciate a fix on this as the message is somewhat annoying.

I tried using the solution posted by lyte_17 and it seemed to have worked with no other side effects...so far.

Here's the solution: Deleting the file "{35379F86-8CCB-4724-AE33-4278DE266C70}" on the "extension" folder located at the backup folder of the history and bookmarks of mozilla.

Thanks, lyte_17

I wonder what this file was for, or if by deleting the file, it might put my browser at risk for something? If someone can shed some light, it will be appreciated.

Just found out that the file "{35379F86-8CCB-4724-AE33-4278DE266C70}" is for the Orbit Downloader, which by deleting the file, it got rid of the downloader extension and its function. I then reinstall Orbit Downloader, and had to manually enable the function. Everything works now and no more error message on start-up.

Hi pirateDan, for future reference, the Help > Troubleshooting Information page is the best resource I've found for determining which folder names correspond to which Extensions.

So that's what it's for haha. Thank you for shedding light on that pirateDan.

Mine was fixed by disabling Avanquest safe search...In my extensions.

"ERROR6: TypeError: Components.classes[cid] is undefined"

I get this error when trying to run my IVONA txt to voice reader extension in firefox.

don't have youtube downloader..

Any fix for it?