Background (2024): Created my userChrome.css file, on my desktop, 4 or 5 years ago when I was using Windows 8.1. At best I am an experimenter with userChrome. Last year, due to another problem, I had to update to Windows 10. So far, so good. My userChrome file held through the update. Fast forward: In May I had a hard drive crash (total DOA) and had to buy a new desktop (Dell) with Windows 11 (I almost regret that), 64-bit. Also using FireFox 127.0.2. After more than a month, most of my software and files are working again. Current problem: My userChrome file is not working as it used to. I had it backed up to other places, so I know it is not the file. I am missing the “tabs bar”; the one with the FireFox icon at the far left, then (in my case) a Google box, and then the “+” for Tabs. That bar is missing and I can not figure out why. I suspect something changed in Firefox. I do not see how Windows 11 (god forbid) would do anything like that. See attached image. I can not create additional tabs or move between them. I suspect that the “solid” black bar after the Bookmarks toolbar(s) may be involved. My “colors” seem to be OK and the location of everything else is acceptable with the exception of the “Find in this page (Ctrl+F)”. The ‘magnifying glass is in the correct place on the second bar but the box to enter data is at the bottom. The box used to be just in front of the ‘magnifying glass’. Not as critical as the “tabs bar” but annoying. Don't see how to attach my userChrome.css (as userChrome.txt). I can supply the file or post it. Can anyone make a simple suggestion for a simple senior citizen?