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When I watch videos in full screen using Firefox browser, the taskbar at the bottom of the system still appears below.And it blocks some of the operation buttons, making it impossible for me to perform operations such as "fast forward", "pause", "volume control" while watching the video。 It seems that we haven't achieved true full screen display.

However, this situation does not occur in other browsers.

What's going on here?

I used the CSS animation property called animation-timeline , which is written as:

element{ animation-time: view(); }

When I view the webpage on Chrome, Edge, Opera, and even on Phoenix browser, the animation works.

It is only on Firefox that the animation does not work. I even added the Vendor-prefix of " -moz-animation-timeline " to the CSS property, and it still didn't work on Firefox, while it is working on all other browsers.

The CAN I USE website ( https://caniuse.com/?search=animation-timeline ) tells me that Firefox does not support it at all.

It however said that I can enable it, by setting "layout.css.scroll-driven-animations.enabled" to true.

1.) I don't know what that means.

2.) Would my website's users be able to see the animation on their Firefox browser, if we assume that I make this setting ?

3.) I am using Firefox version 138.0.3 (64-bit) : What can I do to see that both I and users of my website are able to see this animation on Firefox ?

Regards.

Since the most recent update a few days ago Firefox (on my desktop PC) has been looking and behaving differently. The bookmarks sidebar has disappeared and can't be brought back in its previous form. Selecting Bookmarks toolbar - always show' does nothing. There is no 'Back' arrow to return to a previous screen. I'm finding this new version almost impossible to use. Have I done something wrong? Can I go back to the previous version of Firefox? Regards, Peter

I recently upgraded FF on this computer and can no longer sign in to my att.net email account, although I was able to sign in on another computer on FF earlier today. I just get an error message and Att can't help...is there a setting that has me locked out? I can also access email on other browsers just not the FF version on this computer.

In firefox, an extension no longer appears in the toolbar. It used to. Therefore I can no longer log in into that extension nor can I restore it to the toolbar. My version Firefox 138.03 64-bit. The extension is Phantom version 25.16.0

Started a couple days ago

Youtube works fine for everything, except when i try to watch a video, the rectangle where the video is supposed to be appears black during loading (normal) but then vanish.

checking the console i get a huge error that's just unreadable for me

it doesn't happen on edge, or in private navigation

turning every addon off doesn't fix the issue, and it does it even in "troubleshoot mode"

i haven't "refreshed" because i don't know what kind of data will be lost when i do that

Lately, whenever I try to open a PDF from a website open in Firefox, the tab crashes and the PDF does not open. An error stating that the Windows file-dialog has crashed is displayed at the top of the tab. I tried to attach a screenshot of the error but that action only generates another error.

This condition does not occur when I try to open the same PDF from the same website open in either Chrome or Edge, the PDF opens properly which leads me to believe the problem is in Firefox and not my Adobe installation.

Thank you

I've asked about this before but got no help Firefox is my browser of choice. Occasionally, I find in necessary to use Chrome.

The vast majority of time, when are both are active at the same time, one or both crash, like today. Firefox closed abruptly, then the crash report appeared. I have the crash report. Chrome froze up, and had to be shut down in Task Manager.

It only occurs in this scenario. Rarely does Firefox crash otherwise.

Can someone please advise where to go to get help?

According to the most recent update page, this function should be working for all users by now. (see attached screenshot).

It is still not working for me. Has the timeline been postponed? Is anyone else still unable to use this function?

Thank you!

the tab groups page i was shown by firefox says i should be able to group my tabs starting at the latest yesterday but my tabs still just move out of the way and refuse to group. i found container groups but they work nothing like the page showed. i have firefox version 138 and the tab groups was starting to be roled out on 137

After a Firefox update, my bookmarks menu, which was on the left side of the screen vanished. I have not been able to restore it. When I click the bookmark box (at the top of the page) I get three choices showing up on the upper left side of the screen. 1) Summarize , brainstorm, etc. 2) Tabs from other devices. and 3) History. So how do I get bookmarks???

TNX, Bob

I cannot log in to Firefox and get the tabs I had when I logged out. I get a brand new page and can log in as I please, starting with tab 1. I've looked at every possible entry under the 3 ... menu, and ever entry under File. I've restarted the computer, etc.

I commonly keep windows I am using as reference for research I'm doing and don't add every item to a bookmark until I've conclude which I should keep. This same event happened a year ago and I'm quitting Firefox after close to 30 year of use unless I can recover, and learn what caused this.

It has opened and closed fine literally hundreds of times, now it's as if erased the past but will reopen fine and start over without having to download Firefox again.

I'd rather recover than start over. Help if you can, please.

I used to be able to take a block of emails and delete them all with one click. Now I have to open everyone individually to delete it. Sometimes when I see what it's about, or who it's from. I just want to send it away to the trash.And I can't do that without opening it first. How do I change it?? before I would highlight the first one that I wanted to delete, hold down the shift key and go down to the bottom one that I want to have deleted in the list and all of them would highlight, and I could hit the delete key and they were all gone. I can't find a police in settings to fix that problem.

Hi, In the last hour FF has stopped working completely. I made the mistake of using Ccleaner, which is probably the problem, I haven't had issues cleaning before, though I usually check the registry before deleting and don't recall seeing any entry for Mozilla (I may be wrong, though).

Firefox was working fine a couple of hours ago, but now it won't open at all, except in admin mode and then it won't open any links or tabs, not even settings. I've uninstalled FF, deleted the folder in the Programs folder, and reinstalled it from scratch, but there is no change (the one difference is that it wouldn't open in Admin after before I reinstalled it). Waterfox doesn't open either, but Thunderbird seems to work with no problems.

Thanks, Matt

Using 2025-04 Cumulative Update Preview for Windows 10 Version 22H2 for x64-based Systems (KB5055612) Firefox 138.0.1 (64-bit) and says it is up todate. I have looked at the about:config to find the browser.tabs.remote.autostart but it does not exist in the list of processes. I have also unchecked in settings both performance options intermitently to try and correct this problem, but nothing happens: (unchecked) Use recommended performance settings Learn more These settings are tailored to your computer’s hardware and operating system. (Unchecked) Use hardware acceleration when available Nothing pops up to allow choosing a different number as many support articles say. I have AdBlocker running as an add on and turned off the duck duck go privacy essentials and still nothing stops these insane amount of processes clogging up my computer. right now, on this page there is only this tab open and there are 13 processes running. Please send real fix instructions- thank you

I cannot figure out how to add my favorite things to the toolbar. The toolbar doesn't even show up at the top of my page. I just get a string of random bookmark names under the address bar with the Other bookmarks folder at the end. I can't even get rid of "Finish Setup" which is the last one shown. How do I do find where the toolbar is hidden and get it to show? Once I do find it, how can I add my favorite items to the toolbar? I even had ask a question online to find out how to restore my most recent bookmark which was backed up in the documents folder on my computer. Any suggestions would be very helpful. I don't like the way Mozilla Firefox looks now. It isn't as easy to use. I have included what the top of page looks like now. I am sorry I didn't think to keep one of how it used to be.