Firefox Frequently Fails to Fully Load Web Pages

[aslog]

For some time now, Firefox has been unable to fully load certain pages. Even after refreshing the page (F5) several times, it often remains incomplete. This issue is not limited to any specific website; it occurs across different sites, but it happens very frequently in YouTube Studio.

[tiger71tiger]

mine too fails to load complete page. facebook is not a problem on other browsers

[dftf]

@aslog , @tiger71tiger : an extension you use might cause this

Try "Troubleshoot Mode": go to the Firefox menu -> Help and Report -> Troubleshoot Mode...

Test a site you each have issues with in that mode; if pages then load fully, it'll be an extension causing your issue normally, so you'll have to see which one.  Start by looking at ad-blockers (e.g. AdGuard, AdBlock, Ghostery, uBlock) or script-blockers (NoScript), as they are the likeliest cause.  But extension that theme a page (Dark Reader) can sometimes cause pages to load slower too.

You can see all the extensions you have installed via: Menu -> Extensions and Themes -> Extensions
Some extensions can be disabled on a per-site basis: click their icon in the top-right area of the browser (to the left of the three-line, Firefox menu), then look for an off setting

Or for YouTube and Facebook specifically, any extensions you use that are specific to those sites (e.g. RestoreYouTubeDislikes) are worth looking at too.