On Aug 14th 11 PM ET/Aug 15th 03:00 UTC, due to scheduled Firefox Account server maintenance, users may not be able to sign in or create a new subscription. This is expected to last approximately 30 minutes. Status updates can be found at https://status.vpn.mozilla.org or https://status.relay.firefox.com.

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

After update to 37.0.2 Firefox very slow, videos stall, pages load slow

more options

I had version 13.0 before the update but I haven’t updated for many years because before that one automatic update caused a lot of problems which couldn’t be fixed for a long time and reverting back to the previous version was not possible. Months later if not about a year, one of the subsequent updates 13.0 fixed some of these problem and I decided to turn off the automatic updates to ensure things don’t get worse. So, I had a long period of decent experience but a few days ago Firefox started to crash and quit all the time shortly after starting and even in Safe mode. I tried many things but the only thing that fixed this problem was updating. Now crashing is fixed but Firefox is now so slow that it is useless. Comparing to my other web browsers, all web pages load noticeably and many annoyingly slow and all videos including those on YouTube stall very often and sometimes for minutes . Safe mode doesn’t make a difference. I have tried all suggestions listed on Mozilla Support like Refreshing Firefox, ensuring the Security walls are setup properly, even trying to install Media pack which was not applicable for my computer, and etc. Nothing helped so far. I don’t have any of these problems with the other browsers, Chrome, Microsoft Explorer, Safari, and even Torch. But Firefox was my favorite browser because of its features like Bookmarks, Interface, Color management, and others. It will be very bad if I have to switch to another default browser.

Please help, is there anything else that can be done ? I'm using Windows 7 Ultimate with the latest updates

I will greatly appreciate your help.

I had version 13.0 before the update but I haven’t updated for many years because before that one automatic update caused a lot of problems which couldn’t be fixed for a long time and reverting back to the previous version was not possible. Months later if not about a year, one of the subsequent updates 13.0 fixed some of these problem and I decided to turn off the automatic updates to ensure things don’t get worse. So, I had a long period of decent experience but a few days ago Firefox started to crash and quit all the time shortly after starting and even in Safe mode. I tried many things but the only thing that fixed this problem was updating. Now crashing is fixed but Firefox is now so slow that it is useless. Comparing to my other web browsers, all web pages load noticeably and many annoyingly slow and all videos including those on YouTube stall very often and sometimes for minutes . Safe mode doesn’t make a difference. I have tried all suggestions listed on Mozilla Support like Refreshing Firefox, ensuring the Security walls are setup properly, even trying to install Media pack which was not applicable for my computer, and etc. Nothing helped so far. I don’t have any of these problems with the other browsers, Chrome, Microsoft Explorer, Safari, and even Torch. But Firefox was my favorite browser because of its features like Bookmarks, Interface, Color management, and others. It will be very bad if I have to switch to another default browser. Please help, is there anything else that can be done ? I'm using Windows 7 Ultimate with the latest updates I will greatly appreciate your help.

All Replies (3)

more options

To test how Firefox runs "uncustomized" on your system, could you do a three-minute experiment?

Create a new Firefox profile

A new profile will have your system-installed plugins (e.g., Flash) and extensions (e.g., security suite toolbars), but no themes, other extensions, or other customizations. It also should have completely fresh settings databases and a fresh cache folder.

This profile will be distinct from and not affect your regular profile.

Exit Firefox and start up in the Profile Manager using Start > search box (or Run):

firefox.exe -P

Please do not delete anything here.

Any time you want to switch profiles, exit Firefox and return to this dialog.

Click the Create Profile button and assign a name like Test37, skip the option to change the folder, and then create your new profile. Then select it and start Firefox in the new profile you created.

If you test sites that performed poorly in your regular profile, do you notice any difference?

When returning to the Profile Manager, you might be tempted to use the Delete Profile button. But... it's a bit too easy to accidentally delete your "real" profile, so I recommend resisting the temptation. If you do want to clean up later, I suggest making a backup of all your profiles first in case something were to go wrong.

more options

Thank you jscher2000, I tried that and running from new profile seem to be better. I decided to get the bookmarks from the old profile using Backup and Restore from the Library window. While importing in the new profile the bookmarks which are a lot and take time this message came: "A script on this page may be busy, or it may have stopped responding. You can stop the script now, open the script in the debugger, or let the script continue. Script: chrome://browser/content/places/editBookmarkOverlay.js909"

I often get script busy messages when using Firefox, and often the only way to continue is choosing Stop script because I'm not advanced enough to do more than that and I haven't paid attention if it was always the same script. I don't even know how to find this location on my computer. I haven't experience something like this with the other browsers and I wonder if my Firefox problems are caused by this.

more options

You might need to let the script continue in this case to get all the bookmarks. (I can't tell whether the line number -- 909 -- is significant, it seems to be a part of the code related to tags you can assign to your bookmarks.)

But on ordinary web pages, these errors can be caused by the protected mode feature of the Flash player plugin. That feature has security benefits, but seems to have compatibility issues on some systems.

There is a hidden setting to disable it that you can try and see whether it reduces the number of slow script errors:

(A) In a new tab, type or paste about:config in the address bar and press Enter. Click the button promising to be careful.

(B) In the search box above the list, type or paste flash and pause while the list is filtered

(C) Double-click the dom.ipc.plugins.flash.disable-protected-mode preference to switch its value from false to true.

This might not take effect until all Flash has been unloaded for a few minutes, or you close Firefox.