hi, thanks for reporting this - can you test if the following steps improve the situation? enter about:config into the firefox address bar (confirm the info message in case it shows up) & search for the preference named layers.omtp.enabled. double-click it and change its value to false and restart firefox once for the change to take effect...

Nothing changed.

Is any way to export settings in both modes (safe and normal) to compare them?

according to other users with the same issue, disabling hardware acceleration helps & it's off during safemode too: Firefox's performance settings (requires a restart of the browser)

It works. But I will continue to investigate the problem, because is has no effect on another Win10 account (for which hardware acceleration is on).

Thank you very much for Your help.

another account on the same machine? that would be curious... we're tracking the issue in https://bugzilla.mozilla.org/show_bug.cgi?id=1435472 btw - you may be interested in following along there as well... thank you!

Ok. What we have. I had one suspicion and it turned out to be right. Years ago I disabled ClearType for fonts (as described here: http://www.thewindowsclub.com/disable-font-smoothing-windows). When I enabled it and restored hardware acceleration in Firefox, rendering was correct. That's why it worked on the second account (with ClearType enabled).

Amazing that it has worked so far up to version 59.0. I wonder what changed in this version that has stopped working.

great - many thanks for looking into this and coming up with that finding :))

Solidarity of programmers :)

PaSkol said

My FireFox has just been updated automatically to 59.0 version. And from this moment webpages are incomplete (see attachments). Sometimes, when I move mouse over some area, I can see invisible element. I reset FireFox, but it did not help. If I use safe mode, then FireFox works properly (so I could write that text). I have second computer and there is no problem on it with 59.0 version. I hope I have been understood, I do not speak English very well.

I have found that adjusting the display size up or down using the zoom tool in the top right of the screen makes the page load correctly