I-Firefox Community Forum

A few days ago, something happened to the Firefox browser. The speed is simply terrible, sites are loaded for several minutes. Reinstalling does not help. Other browsers work fine.

I seem to keep getting a popup every few hours regarding XULRunner complaining about "This profile was last used with a newer version of this application. Please create a new profile." This will occur every so often, even when Firefox is not open.

I have already attempted to:

• Reboot
• Clear cache
• Uninstall extensions
• Uninstall/reinstall Firefox
• Downgrade Firefox
• Make a new profile and switch to it
• Delete all previous existing profiles

I think I've run out of things to do, anyone got a silver bullet for this thing? I was unable to find anything conclusive with Google, so I figured I'd ask here.

I tried all common troubleshooting steps: deleting cache reinstalling different settings turning off adblocker/vpn disabled efficiency in task manager and set it permanently to off in FF

I used to have 1000+ tabs in 2016 no issue. I had problem in past with Firefox using 100% CPU which now it is not using only like 50, but memory is getting full 89% i use also large page file on ssd. Problem is even when i restart firefox it is slow with low RAM usage! SO that's not it! Even 5 tabs sometimes it is slow!

It is so damn slow it drives me crazy! I tried also Quantum in past when Firefox has 100% CPU usage bug and it was only tiny bit better but still caused 100% CPU usage!

All other browsers are anti user cannot even stop Autoplay literal terrorist Firefox is only normal browser unfortunately performance compare to 2016 got absolutely abysmal! I had this problem even in-between reinstals of OS so it doesn't seem it is me. I play demanding games no issues on my PC...

When I open Firefox it opens a maximized window with tabs, then it opens a minimized with a single tab, then it reopens a maximized window with all session tabs. Each window displays in succession, one window at a time.

I'm on desktop using Windows 11.

I just read a post saying this behavior was caused by the resist fingerprinting feature. Can someone explain how that causes the repeated opening of browser window 3 times. Is there a way to retain the anti-fingerprinting behavior w/o the multiple window opening behavior?

I have just installed Firefox on a new iMac, running MacOS 15.2. Firefox will not load any of the websites I have tried, whereas Safari and Chrome do. I have cleared the History and also set "No proxy" but loading still fails.

when I start firefox, it tells me the old one is running and to close it. i hit the close button and keep getting the same message. I have uninstalled firefox and reinstalled it and keep getting the same problem.

I am trying to access iDRAC 7 on a Dell Poweredge R520. On version 133.0.3 I get a An error occurred during a connection to 192.168.1.20. PR_END_OF_FILE_ERROR. I know that the problem is that Firefox stop supporting older versions of TLS. So I choose to also install an older version of Firefox (43.0). On that version I get a The page you are trying to view cannot be shown because the authenticity of the received data could not be verified error. I used to have no problems accessing iDRAC 7. Has anyone else been able to resolve this problem?

I like firefox...used it two to three times a week for over ten years...Now when I click on the icon on my menu, I am greeted by the ansurb: "That doesn't look right." When I try to download Firefox, it will not down load...why are you idiots doing this to your own product?

Subject: Assistance Required for Frequent Firefox Crashes on Ubuntu

Dear Developer Team,

I am facing persistent issues with Firefox crashing on my Ubuntu PC, and the problem has been ongoing for the past 40–50 days. Despite multiple attempts at troubleshooting—including uninstalling and reinstalling Firefox, clearing all caches, and other measures—the issue remains unresolved.

I’ve noticed that Firefox works for a few days after reinstallation, but then problems begin to surface, such as a half-screen display. Eventually, after restarting the PC, the browser starts crashing again.

Could you please investigate this matter urgently and provide a resolution? Additionally, I would appreciate it if you could clarify whether this might be related to a RAM issue or some other underlying cause.

Looking forward to your assistance.

Best regards, zimmi

When saving images from websites using the save image as feature, Firefox will freeze up and not register any mouse click or anything instead making a ding noise every time is register a mouse click. This will continue for like 30 seconds before it becomes normal then it will repeat this for every image. How can I solve this?

I have read a number of reports of tab crashing, which I have continually. Running 133.0.3 (64-bit) on Win 11 Home 23H2. Very inconsistent crashes, sometime will open new tabs other times it will crash. I have reinstalled no change. I ran refresh, no change and now when I open Firefox I get a message to restore windows. I can't seem to get that message to go away. Any suggestions, especially about the opening message? I have used FF for years and am almost at the point of switching to Chrome. As an aside, also have problems on some websites processing information/orders when using Firefox. No problem when I switch to Chrome. Thanks in advance......

I believe this problem began in 133. I've noticed that if FF is open for a few hours, it starts to develop a very noticeable input lag. For example, if I'm watching a YouTube video and hit an arrow key to advance the video, there will be a couple of seconds before the browser registers the key press. It behaves like a high CPU issue but I do not detect high CPU usage when this is happening. Restarting the browser resolves the issue for a few hours.

This is happening on Windows 11 as well as on a Mac running Sonoma.

I get a message "We Encountered an Error" Please restart your application to try again. It continues to pop up (only when I'm in Firefox) and I click the button "close" and can continue until it pops up again. This just started today. Is there anyway to get this to stop?