Firefox Community Forum

"The bookmarks and history system will not be functional because one of Firefox's files is in use by another application. Some security software can caused this problem".

How do I resolve this problem?

For some reason text rendered in canvases (used by Minecraft hostings to display console) is distorted. I'm not getting this behavior in other browsers (including Zen – Firefox fork). The issue persists in both stable and nightly versions, with and without hardware acceleration, in safe mode too. Any clues?

Firefox recently sent out its monthly newsletter (Oct '25) with all sorts of options that can be enabled on Firefox. I'm a computer illiterate & foolishly chose some of the options -- don't remember which nor know how to discover them.

Now javascript is no longer enabled on my MacBook Air (macOs Big Sur 11.7.10). I cannot access my protonmail account and many many other sites.

I've gone cross-eyed accessing "fixes" that are labelled "only for advanced users" & am bright enough to not even try.

Is there a simple fix (short of wiping my computer -- with data going back 11 years) that even I can do?

If you have "fixing your firefox for Dummies" then please email me with a solution. [edited email from public community support forum]

After every update, Firefox starts to a blank screen and will not start loading the webpage url put in for over twenty minutes to a half hour. During this time other browsers on my Win 10 PC load immediately so it is not a network issue. It is Firefox. When I see that an update is pending I hesitate to do the update because I know I will lose the use of Firefox until it is ready to respond. It just hangs with "loading X.com" showing at the bottom left of the blank screen. I have been using Firefox for a long time and in the past year or longer it has become very unreliable. There are also instances where without an update it will do this and the only way I can get it to work is to clear the cache and the history through settings. What is going on with Firefox! (And lately there is an update every couple fo days!

Youtube just does not run well on the firefox browser, I have had this issue on my pc, as well as my laptop. Twitch, piracy streaming sites, 9anime all work fine this problem with loading and buffering is exclusive to youtube. I have tried resetting my firefox settings, changing the values for load times and resource usage in about:config and none of these have fixed my youtube.I have tried multiple fixes I've been recommenced by online forms. I have switched my user agent to make youtube think I am using chrome, I have disabled and removed all of my extensions including ublock origin, and loading youtube remains painfully slow. In fact, disabling adblock makes the load times even slower.

Also responding to my post with "hmmm durrr it works just fine for me" does not help anybody, stfu.

I've loved Firefox for years but can no longer use it because I have been unable to resolve this issue. All was well, an update was done, and bingo, I got this message. I don't know how to fix it. I removed Firefox from my desktop and re-installed. Same problem.

"The bookmarks and history system will not be functional because one of Firefox's files is in use by another application. Some security software can cause this problem."

Since recently 1~2 version, my Firefox keeps consume large amount of memory and release it repeatedly

Even I restart Firefox and do nothing, it will start doing this again

I use about:processes and about:memory to capture this seems the main process's "tab.query" causing this, please check

PS: sometime it will consume till system max (64GB) and cause my OS out of memory. PS2: that wave-like memory usage is cause by Firefox

I'm using the vertical tabs feature. I also tried enabling the "Expand sidebar on hover" option, which minimizes the side bar, and only expands it when you hover on it.

Issue: I have a lot of open tabs, and I'm usually working with the ones at the bottom of the list. When the bar minimizes the scroll position resets back to the beginning. So, every time I want to select a tab, I have to scroll back down, which makes this feature very hard to use.

Expected behavior: After the vertical bar minimizes, and I hover again, it should keep the scroll position.

If I need to upload a file I click on the OPEN or BROWSE button in the website, Open File dialogue opens trying to list the location it is already looking at, and it hangs for over 30 seconds before listing files. This is windows 11, but it did it when i had windows 10 too. I dont know what to do.

When using any Microsoft 365 product on the browser I keep getting a prompt to "Please sign in" although I am already signed in. I can click the Sign in button and a about:blank page pops up for a split second. Then within a half hour or so, it will pop up again. I deleted my cookies but the problem still persists. Does not happen on other browsers.

Whenever i search something on google, firefox desktop (all fine on android) is failing to display the ai(gemini) answer no matter what questions i ask.

Same happens in the "AI Mode" option that is available in google's recent update.

And, I,m logged in.

This started since a week, everything was working fine before that.

Adding the images below.

I ran the windows 11 system file checker (sfc/scannow) to fix a font problem I was having. It did say that problems were found and fixed and I do not seem to have that problem any more. After that, i could not access the Settings in Firefox. I uninstalled and reinstalled Firefox and still could not access Settings. I also cannot access any Web sites either by typing them into the address bar or using bookmarks. Both Chrome and MS Edge work.

I watch Rakuten Viki, and suddenly a recapcha box is popping up on the bottom right, blocking the full screen button.... so annoying,,,, how can i get rid of it/ THANKS

I just got a new Epson 3-in-one printer and tried to sign up for the warranty. I got a message that the warranty was expired... I went to the Epson support site on Firefox and Malwarebytes blocked the site as malware... It said I could add the site as approved, but I don't know how to do that. "https://www.epsoncom.com/my-account/home". The Epson site said I already had an account but my password was incorrect. I had an Epson printer more than ten years ago; I don't remember the password and they don't provide an option to reset it. HELP, PLEASE.

The comment sections for foxnews.com and other sites disappeared using Firefox but not when I switched to Chrome. This just happened 6-18-25. Before this date, it worked on Firefox.

Using Firefox, my gmail inbox is my home page - and has been for several years. As of yesterday, the page opens but the page is blank. I am not aware of any changes that I have made.

I do not have this problem using chrome on the same device or firefox on other devices.

Probably something simple, but I have no idea what.

Thank you