Forum communautaire Firefox

So, after using firefox in the background to browse websites or watch videos I checked my memory usage in firefox with about:memory -> Measure and saw that youtube was consuming a decent amount >2GB (checked the main url when clicking the youtube src, it was the video on that sole tab i was watching and nothing else playing youtube in the bg) so i closed that tab, waited a bit and re-measured but then see that the memory usage for youtube rose about 200MB... and the website for youtube is that same url for the tab that i just closed (when checking the src in the results for Measure). I've been revisiting the about:memory page, reloaded it and re-Measured and youtube is STILL THERE. Even now, 10 minutes later i still see youtube there, with none of my tabs running youtube.

If i close firefox entirely and re-open my tabs then it'll very likely fix it but this has to be a major issue no? I shouldn't have to close the entire browser program just to fix a website visit, which is youtube of all websites.

As of this moment, firefox, with 8 tabs open, is consuming 4,452.99MB (~4.5GB) where 2.5GB is youtube for that page i closed.

I don't know if sharing memory reports from the about:memory page give my cookies away or leave me open to a similar vulnerability so I won't share it unless a dev or similar asks for it but for now, I've included an image showing all the tabs i have open on firefox, 2 windows.

Here's the message I get 'intermittently when I open Firefox, which is my default browser:

Fix "The bookmarks and history system will not be functional" error message

The "fix it" page doesn't suggest any possible security program obstacles. Can you help me find the culprit?

I still have windows 7 pro on my computer and now I keep getting "Access Denied" from some websites Can your ESL be used on my computer so that I can access my bank; stores, etc.?