Forum d’assistance Firefox

After updating my openSUSE Firefox package from version 122 to 123 every frame inside each window started to have weird grey overlay of scrollable area. I failed to find any description of such a thing happening, let alone how to get rid of it. I tried removing build-in distro-default preferences and had complete audit of all my custom preferences in about:config but none changed that behavior. I even updated to 124b4 but this also haven't changed anything. Naturally, nuking entire profile is not an option, I might as well replace the whole browser. So, how do I get rid of this thing?

Using firefox version 102.3.0esr (64-bit) on openSUSE Leap. Since a couple of weeks the opening of external links by clicking a link from any application or when running firefox <url> is taking about 5 seconds when the browser is already open. This was always instantly and still is on same setup on laptop machine, both are updated to the most recent OS packages.

I've tried safe-mode, new profile, copied profile from the laptop, searched online for references but so far I can't pinpoint what the issue seems to be.

Any kind of information as to resolving this issue would be greatly appreciated.

I have Firefox 50.1.0 on openSUSE 13.1 Linux (KDE desktop). This is the last update from openSUSE, but is now deprecated by some websites. I am reluctant to download a recent Firefox version without knowing in advance that it will work under SUSE 13.1. I am familiar with 13.1 and reluctant to update that, merely to run a new version of Firefox, as it will create complications with my multi-boot system, which includes a MSDOS 6 partition for legacy software (it took me ages to get GRUB configured to load that reliably and I'm not sure I could do it again).

Please advise what is the latest version of Firefox that will run under my elderly version of Linux and how to obtain and install it (I am not an expert Linux command line user). I am using Firefox 106.0.3 under Windows 7 to send this to you (multi-boot system), because I could not sign up with 50.1.0.