Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance).

• Do NOT click the Reset button on the Safe Mode start window or otherwise make changes.

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

I'm running Social Fixer to block suggested posts on fb. I wondered if this was a possible cause.

Hi idowning

That is quite possible.

Did you try to disable this extension?

Yeah, the problem stopped under "restart with extensions disabled" so I went to help/troubleshooting information/reset and it reloaded with all my favourites, history etc intact. Thanks a lot

I started getting these two errors immediately with the 22.0 upgrade. I am also running NoScript 6.2.2.2 (auto-upgraded simultaneously with Firefox) and SocialFixer; but the latter should only run if I'm on a Facebook page. These errors happen on lots of pages. They stopped when I blocked "Facebook Connect" and "Facebook Social Plugins" in Ghostery.

The problem went away when I upgraded SocialFixer (and Ghostery, which was another automatic upgrade). Between auto-upgrades of add-ons and FireFox itself, it's hard sometimes to maintain control of what changes are related to what possible new problxxxx features. :-)

Case closed (for me)

The solution to fix this bug caused by Mozilla Firefox 22.0 update, you simply upgrade Social Fixer here: http://socialfixer.com/blog/category/releasenotes/

As I suggested above, I had already made this discovery. Thanks

Well, that didn't work for me, because when I try to go to the Social Fixer website in Firefox I get an error message.

This is getting extremely irritating! I've disabled ALL of my extensions, and still getting these -

evalInSandbox:Error: Permission denied for <https://facebook.com> to create wrapper for object of class UnnamedClass

and

Error: Permission denied for <https://facebook.com> to create wrapper for object of class UnnamedClass

Where do you find restart with extensions disabled??

Hi pgurney

You can find that in the Help menu in the menu bar or under the orange Firefox menu button.

• Help > Restart with Add-ons Disabled
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

Yes, updating social fixer did it for me too. Actually, this is a new computer (OMG, fast as HELL, 16Gb DDR3 and a real SSD hard drive!) and I did not have Social Fixer installed. Once installed, the error went away. Thanks everybody! Here is the link for those that want it. This is good stuff, people!

Download Social Fixer

I'm getting the same error messages as others here, and I've disabled the extensions. I'm loathe to use SocialFixer as the only time I used it, not long after installation I found that it blocked things I didn't want it to so no longer use it. Perhaps I didn't investigate all its options thoroughly, but for now, I just want the error messages to stop! Anyone any other ideas please?

Is this happening with the current Firefox 23.0.1 release or with a beta release or Nightly/Aurora build (the OP that started this thread was using an Nightly (a1) build)?

Create a new profile as a test to check if your current profile is causing the problems.

See "Creating a profile":

• https://support.mozilla.org/kb/profile-manager-create-and-remove-firefox-profiles
• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues

If the new profile works then you can transfer some files from an existing profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over the problem.

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

I had the problem when I upgraded to 22.0, and it went away when a couple addons were updated, Socialfixer among them. I'm at 23.0.1 or 23.1 (or whatever the latest release channel version is) and the problem has not recurred. I consider this to be closed (as far as I am concerned).

Hi Cor-el

I should have mentioned; I'm running 23.0.1

Creating the new profile worked. Facebook didn't throw any errors up. I was about to ask the $64,000 question "How do I know which files aren't corrupted" when I read the "Transferring your data..." page. That's something I'll do in the future as it looks like I'll need to concentrate and lie down in a dark, quiet room to do it. That's a luxury I don't have at the moment :) But many thanks for your help so far.

md140963, creating an entire new profile can be quite a long, arduous project if you are a heavy Firefox user and have installed and setup all of the add ons and plugins that you need and want. That is like killing a fly with a sledgehammer. It will work, but might mess up the walls quite a bit. :)

I am a PC user for decades but am not a programmer. IMHO, the problem is with the updated Facebook code and the most recent Firefox version to interpret it. I think if left alone long enough, one or the other would update to make the issue go away. Social Fixer is actually a pretty neat and free tool. It can change or alter many things on FB or, be so tamed down it essentially does nothing. Up to you. You spend a bit of time in the options, get it the way you like, and in the User Preferences you can export your settings, save them, import them, clear them, or reset them. So you never have to go all through it over again if an update wipes your changes out.

That, to me, is a LOT easier and quicker than creating an entirely new profile that is essentially a carbon copy of my original profile. I have 31 extensions for Firefox installed and setup. Maybe I can trim some of it, but I actually use almost all of them daily. Some occasionally but when I need them, they are there. I took an online 4 hour driver school test for a traffic ticket and quickly found out that it would take over 12 hours to complete this test! That is NOT FAIR, I only had to do 4 hours and when I called to complain about it, I was told that all the questions in the test were necessary to meet the requirements of DMV and I had not choice. So, I installed Fireshot and cheated my way straight through the test, passed it, and was done in a jiffy. Fireshot lets you capture web pages complete, even ones that scroll all the way down. So I just copied every page, and when I got to the test, I searched my Fireshot folder for keywords, found the answers, and just put them into the test. Cheating? Yes, but paying 12 hours for a 4 hour test is not exactly a fair trade. So, I did what I had to do.

If you like to tinker and spend hours on it, sometimes I do that, then go for the new profile. But if you just want to get past it and move on with your browsing, install Social Fixer and turn everything off. My 2¢.

Good luck!

Must admit, ohmster, that I am fairly IT-literate, but the thought of doing all the moves one at a time to a new profile is not something I want to consider in all honesty. I'll give Social Fixer another go and if all else fails, I'll wait until Mozilla / Zuckerberg sort it out between themselves :)