Firefox Community Forum

I'm getting the following error message:

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.

I don't know what prompted this concern on my Windows 11-based laptop, but I only noticed this last night doing some research for another issue. I don't have any of my bookmarks showing up in the bookmarks section, nor will it allow me to click the star on any tab to bookmark the page. I have restarted and shut down my laptop several times and this is not solving the concern. Let me know if you need more information or if I need to start this inquiry again elsewhere, but again it sounds like the same concern.

I have included a screenshot of the exact error for accuracy's sake. Like everyone else here, I'm trying to get my bookmark and history access back up and running but not sure how to go about it.

I couldn't get past the first fix suggestion because I am not sure how to restart Firefox (https://support.mozilla.org/en-US/kb/fix-bookmarks-and-history-will-not-be-functional?as=u&utm_source=inproduct&redirectslug=The+bookmarks+and+history+system+will+not+be+functional&redirectlocale=en-US). I have restarted my laptop several times but the issue still persists.

Please advise.

Ironically, I am not having this issue on my older PC that is still operating on Windows 10. I can view history and access or add bookmarks with no concern to my knowledge.

All the tabs, in both my profiles are constantly crashing. I cannot keep at a task for more than a few minutes without needing to restart the tab. Is this a setting problem? I've cleared the cache, and reset Firefox, to no avail. Thank you for any relevant advice and/or assistance.

Hi this can anyone shed anylight on this please? I was using Facebook earlier today with no problem then now it won't run nor open yet it runs fine in Google Chrome. I've cleared out the Cookies ect and re-tried but its not pitching anything.

Many thanks Rob

I just updated Firefox to version 151.0. The release notes say:

"Private Browsing Mode now allows you to instantly clear all data from your current session without closing the entire window. When you select the End Private Session button (the fire icon) to the right of the URL bar, Firefox will ask you to confirm to clear your session. Once confirmed, it will wipe all of your private browsing data and open a fresh new Private Browsing Mode session for you."

There is no "fire icon" in my toolbar in private browsing windows. I have tried resetting my toolbar to defaults, but that didn't help. I re-installed Firefox 151.0, but that didn't help. I re-booted my system, but that didn't help. I have run out of ideas.

Can anyone tell me how to get this button to appear in the toolbar in private browsing sessions?

I'm using Windows 11 25H2 on a Dell XPS 9630 tower computer.

Thanks, Bill

I have been using Firefox profiles for years, long before the announcement of the new profiles UI. The new profiles UI launhed with FF 144. I'm on the latest version, which is 149.0.2 and I still don't have the new UI. Specifically, I do not see my profiles in the new UI.

When FF launches I see the new UI but my profiles are nowhere to be see as you can see in the screenshots:

https://postimg.cc/gallery/tFXz00m

I have 2 profiles and they each have their own name.

Instead I am presented with 2 option "Original Profile" and "create new Profile". When I click on orignal profile, Firefox opens my default profiles which has its own original name. However, when go throught the new UI o switch profiles, I do not see my other profile. Moreover, if I click manage profiles, I don't see either of my profiles.

The only way I am able to launch my 2nd profile is the old fashiong via "about:profiles".

Why can't I see my profiles in the new UI?

On my 2nd profile, I don't even have the new profiles UI.

Why dont't I have the new profiles UI months after you launched it?

Please help!

Why when I search ABOUT:BLANK TAB, an empty page displays instead of the site I am searching for? I then have to go back and try again and again until it finally displays.

Cleared Cache, searched for extensions and not sure what to look for...they were verified by apple to be "normal". What else? Macbook Air 2023 running Sonoma 14.8.1

I have noticed that since around Friday, April 24th, 2026, that Youtube videos will sometimes refuse to load properly. The page for the video will come up, but buttons on the page will not load, and nor will the video. This started happening around mid-day, when prior to it, things had been fine. At first I thought it might be tied into the 'ambient mode' option on Youtube itself., But even after shutting that off, I found it was still happening at ranodm.

Is this something new Yotube is doing in their continued (idiotic) fight against ad blockers, or is there an actual glitch in the browser or, more likely, a glitch in Youtube? Like I said, this seems to occur at random and I can't trace the cause for it. I'll include a screenshot of what I'm seeing. But if anyone knows what's happening here, I'd appreciate it.

I should add that I am on Windows 11 and using the new version 150.0 for Firefox. (Congrats on that, by the way.)

I'll be honest, I keep hearing some other browser can block youtube ads innately. (Brave, I think it was called?) and while the idea is cool, I'm not giving up a browser I've used for over 20 years for it. If Firefox can find a way to implement a similar means of blocking Youtube ads innately, I;d love it. But for now, I just wanna know what the devil is happening with the site. Can anyone help?

I understand that VPN was progressive roll out, but I have been able to successfully use it for the last two months. Today I upgraded to version 151.0.4 and the VPN icon was no longer up in the toolbar. I thought maybe I did something wrong and went back to customize and put it back on, but it's just not there anymore.

Did you decide to roll it back without warning?

History drop down-Restore Previous Session MENU OPTION AND Recently Closed Windows MENU OPTION tab choice ARE DARK!!! Not active!!! Why? (If they are there to be seen they should always be active for use)

I use these ALL THE TIME!! Where is that function??? Why is MY history from yesterday NOT there for me?? I need it right now!

My life is busy and stressful enough without Firefox or Apple or Microsoft adding to it!!!

btw am waiting full 5+ min for a simple screenshot to "upload" to Firefox help below so I can hit send on this?? Still see the word "uploading" - are you finished yet Firefox?

Apple computer w/Tahoe OS 26.31

Hello,

My Firefox browser just updated to version 150. I was notified that Mozilla now has a free browser-based VPN. I have followed the instructions listed, but I don't see the VPN option available. Also, I don't recall seeing a pop-up request from Firefox about getting access to this VPN.

Is it possible for me to get access with my account?

Hello,

I have disabled AI according to the instructions given by Mozilla, under settings and AI controls. When I search, I still get the first result as an AI generated result. I want to disable that. I don't need AI's help to understand what I am looking for. I want an old school search without AI.

Is this possible? If not, could you please make it possible?

Thanks.