Firefox 커뮤니티 포럼

9/19/2026 Firefox Version 156.0 (64-bit) for windows 11 up to date with Windows Updates. I often have 2,3,4 Firefox windows open, each with several tabs open. Sometimes, Firefox will just totally freeze, and I can't do anything more. ALL Firefox open windows and tabs freeze. Other windows/apps are fine, and working normally. Only Firefox seems to be affected. The only thing I can do is use Windows to totally close/end the Firefox application. It then closes all the Firefox windows. I can then reopen Firefox, and everything seems fine - but I have totally lost the open windows and tabs I was on.

This has happened across several Firefox updates. I do not think this happened prior to 2026. Maybe just since June 2026.

One Extension - Web Threat Shield

Thanks!

I have version 156.0 (64 bit). It seems like the freezing started soon after the update and it is getting worse. Tonight it is only unfreezing for less than a minute. Some of the extensions showed that they needed permissions updated. Since I could not figure out what they did, I disabled them. None mentioned cursor control or issues that looked like they were nothing but options.

Hi,

I have been using firefox for a while now and realised there is this annoying performance issue tied to my laptop, where firefox keeps freezing randomly while switching tabs or scrolling. It doesn't seem to happen on my desktop pc, and browser such as edge and chrome doesn't have this issue on my laptop, so I am confused as to what is causing it and how I can fix it.

My laptop specs are as follow: GPU - RTX 2000 Pro and intel arc 140T RAM - 64 GB LPDDR5 CPU - Intel core ultra 7 265H

Hi Mozilla team,

I’d like to report a serious issue with Firefox lately. The browser has been performing very poorly and frequently becomes “Not Responding.” In many cases, websites fail to load properly or get stuck indefinitely, even though my internet connection is working normally.

I’m experiencing these issues on the latest version of Windows 11 with the latest version of Firefox. This has become quite frustrating and significantly affects my daily browsing experience.

I hope the Firefox team can investigate these stability and website-loading issues and provide a fix soon. Firefox used to be much more reliable, but recently the overall experience has been very disappointing.

Thank you.

Hi,

Whenever I try to upload any sort of file, the file explorer pop up thing opens, and then freezes. This doesn't happen with any other application, just Firefox, and it happens across websites. Eventually the window freezes long enough that you get the 'close/wait to respond option', and then it closes. Firefox itself doesn't freeze, just the file picker. Nothing ever crashes/closes unexpectedly, and there's no crash reports in the about:crashes thing.

It's not super urgent because you can copy and paste most files but it is frustrating. Any help would be very appreciated.

Thank you

Ever since a recent update, my animated wallpaper for Firefox only plays one frame, and then freezes. If i switch or refresh tabs sometimes it can trigger the GIF to start playing normally, but 90% of the time the background stays frozen, I don't think this issue is related to my PC because the wallpaper was working fine before the Firefox update, and I'm having the exact same issue on my laptop too.

I’m experiencing a strange issue on Firefox where a separate blank/dark window briefly appears over the browser while I’m browsing, then disappears.

The window appears to have the Firefox icon in the top-left and what looks like a Firefox tab/address-bar interface, but there is no visible text or error message.

It happens randomly while Firefox is open, including while watching YouTube. It does not appear when Firefox is closed.

Troubleshooting already performed:

• Windows 11 cloud reinstall using Remove everything
• New Microsoft account
• Defender Offline scan clean
• Multiple malware scanners clean
• Malwarebytes Premium installed
• uBlock Origin (only extension i use) removed/tested, but the issue remained

I took a picture showing the window appearing. Is this a known Firefox issue, background Firefox process, or something else?

Hello there,

I realized that quite often when I restart Firefox (Developper Edition) and restore my previous session (latest occurence with 46 tabs), the window becomes invisible. It still exists, and I can even see it in the Window menu list pointing to my latest tab but it's nowhere on screen. I can add/navigate through/select/remove tabs using the keyboard, I can see them listed on screen when I Ctrl-Tab but the whole window remains invisible.

It'd be great if someone could help me out.

Best regards,

Emmanuel