Hi,

Would you please take a loot at this article and scroll down to the section :

The problem does not occur in Safe Mode

Any good  ?

You can try to disable hardware acceleration in Firefox.

• Options/Preferences -> General: Performance
  remove checkmark: [ ] "Use recommended performance settings"
  remove checkmark: [ ] "Use hardware acceleration when available"
• https://support.mozilla.org/en-US/kb/performance-settings

You need to close and restart Firefox after toggling this setting.

• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems

You can check if there is an update for your graphics display driver and check for hardware acceleration related issues.

• https://support.mozilla.org/en-US/kb/upgrade-graphics-drivers-use-hardware-acceleration

I disabled hardware acceleration, disabled all extension (except two webextensions), restarted firefox. I can't find any newer driver (I also tried to switch form integrated to dedicated graphic card). Unfortunately the problem still occurr.

It seems that dialog windows remains off screen once created. For example Firefox closing dialog (MozillaDialogClass) remains offscreen (position: -192, -131).

I attach a screenshot of what happens when i try to input text in search box.

Thanks

You say that you disabled all extensions - did you do that one by one  ? How about this one : QuickJava 2.1.2  ?

Yes I have disabled QuickJava too, and the result didn't change. I tried again just now.

Btw, Thunderbird never had this problem.

hactar said

Btw, Thunderbird never had this problem.

Now I'm confused : are you saying that you are experiencing this problem using Thunderbird  ? Or are you merely saying that you never had this problem in Thunderbird, but you now have this problem using Firefox  ?

Happy112 said

hactar said

Btw, Thunderbird never had this problem.

Now I'm confused : are you saying that you are experiencing this problem using Thunderbird  ? Or are you merely saying that you never had this problem in Thunderbird, but you now have this problem using Firefox  ?

No no, I never had this kind of problems with Thunderbird, sorry if it was not clear.

hactar said

No no, I never had this kind of problems with Thunderbird,

And you still don't, right  ?

'Just' with Firefox, right  ?

Only with Firefox. From version >= 55.0 (I am using Firefox since Mozilla M8, after using Netscape).

Never with Thunderbird, neither in the past or the present (I can't assure for te future). :)

Changing screen resolution (and switching back) fix the isssue and make dialogs/menu appear again. So I supposed this problem is related to some miscalculated screen size when waking up from standby.

p.s. I disabled all extensions and plugins.

Sadly, I am still having this problem on Firefox 57.