Diễn đàn hỗ trợ Firefox

I have four active Firefox windows, each with quite a few tabs. I have been closing and re-opening Firefox with no issue until today. Earlier this week I updated my Mac OS to Ventura 13.5, and Firefox was still operating normally after the installation (closing and re-opening with all windows and tabs intact).

Today however, when I restarted Firefox, no windows opened automatically. I closed and restarted a few times, and finally one window opened intact; however the other three windows (still dispalyed on the "Windows" menu) refuse to open. When I look at my Firefox app on my iPhone, it also shows all the tabs intact.

What can I do to get these to open? I am running Firefox version 115.0.3.

After removing elements from a website with another add-on, I'm left with a considerable white gap at the top.

I can manually change (pointless) the margin-top property to -100px, but how do I do this with the Stylus add-on?

Stylus doesn't like negative values:

margin-top -100px

10:20 Expected "{" but found "-100px".

Is there a lighter/simpler alternative to Stylus?

When I play a video in fullscreen, there is a strange black border that appears around the video which makes the content smaller than it would otherwise be. This border does not display in Safari or Chrome, just in Firefox. It also occurs in every media player I've tested, including YouTube and Netflix.

Annoyingly, I can't get this to show up in a screenshot. It seems like Firefox guesses the aspect ratio or resolution wrong when it puts media in fullscreen, and it has the effect of downsizing the actual interactive part of the display. Meaning, I can't move my mouse into the border area to take a screenshot of it.

I'm on an ARM Macbook running MacOS 13.5, if that matters.

Is this a bug, and/or is there a way to fix this?

I had something like 7 windows open 10 minutes ago (yes I am a tab hoarder). I was trying to run a game that used a lot of RAM, so I decided that I would close ALL of my firefox tabs in hope that the game would run smoother with the 5gb that Firefox was using. I didn't think anything of losing the tabs because I had accidentally closed windows in the past using the big red 'x', and an easy ctrl + shift + t always restored the entire window no problem. When I tried to open firefox again within the next 5 minutes, only 3 of the windows restored themselves, I assume using the general > startup > open previous windows and tabs setting. Using Ctrl + Shift + T did nothing to restore them. Please help, as the windows that did reopen were the ones that I cared the least about.

Prior to getting some desktop PC upgrades that required a new install of Windows 11 and a new install of Firefox, I backed up my entire PC (yea!).

Now that I have re-installed Firefox, I see that I have none of my saved bookmarks and so I want to restore the Firefox profile - all of it or at least the bookmarks.

I have tried following the Firefox instructions for this, but am apparently not doing it right.

I can't seem to locate the bookmarks file, for starters, in my backed up files. I find the profile but I don't find anything like places.sqlite.

Can someone help me so that I am locating the right (and complete) files, copying them correctly, and then switching to the new/old profile correctly?

Thanks in advance.

Dear Mozilla

I wrote to you earlier today about a problem i am having with themes.I change themes quite frequently and have a lot of them on my list. After opening and closing the browser once or twice the list of themes no longer shows what each theme looks like. I reset Firefox and the image of each theme reappears. It's quite tedious as i said to have to do this once or twice a day. Is this problem occurring because i have too many themes on the list?. I have turned off all other extensions and the same problem keeps happening. I don't know what to do.

/edit: Please put a space after periods as there were unintended links.