Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

every time when i open firefox this shows up Components.classes[cid] is undefined. what is this?

more options

can't explain any more

All Replies (1)

more options

Probably caused by an incompatible extension that you have installed. You need to figure out which one is throwing that error and disable it until the developer of that extension fixes it.