hello, in this thread a user has found out that the problem might be related to the ghostery addon - do you have it installed too?

if so, add an exception for yahoo mail: click on the ghostery icon while you're in yahoo's webmail, choose "edit blocking options" & then don't block on this domain...

I do not have ghostery but I'm still getting this message.

can you try to replicate this behaviour when you launch firefox in safe mode once? if not, then maybe another addon is interfering here...

Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

Thanks for your help. When I start firefox in safe mode, I am able to reply to yahoo email messages and I no longer get the error message.

Now, how do I know what is actually causing my problem when firefox is operating normal, not in safe mode?

To madperson, Oops, my bad. After posting my thank you and saying I didn't know how to troubleshoot my problem, I see you beat me to the punch with the link in your answer to aid in my problem solving.

Upon resetting firefox, I can now reply to yahoo emails!

Thanks again

Hi funkiernyou,

What extension or addon was causing the problem? This is an issue I am investigating right now and any insights would help. Ghostery was only lead we had originally. If you know of something else, please let us know.

Matt

Sorry, don't think I can be of much help due to the fact I did a complete reset of firefox. Per the advice given as seen in this thread.

I don't know exactly what that involves but I'm guessing it wiped out every add-on that I had, thereby making it virtually impossible to troubleshoot exactly which one was the cause of my problem.

I found that the problem for me was having my AVG toolbar enabled. I suspected that might be the problem since AVG recently had me update the toolbar. I disable it to send an email and enable it the rest of the time. It is a pain, but significantly less of a pain than not knowing the issue.

Honeybear's solution is the one that worked for me. I'm using Firefox 20 so I just went to Tools|Add-ons|Extensions and disabled the AVG SafeGuard toolbar. THANKS FOR THE FIX HONEYBEAR!!