White border around Firefox and unable to resize
I have a problem with Firefox where a white border is displayed around the sides and bottom of the window and I am unable to resize the window. No other applications appear to have this issue.
If I have more than one Firefox window open and click between them on the title bar, a classic Windows title bar and buttons is briefly displayed before being repainted. You can still see these slightly as part of the white border in the attached image.
Here's a summary:
- Windows 10 Professional, latest updates installed (Version 1903)
- Clean Windows installation, barely any applications installed
- No Firefox add-ons installed
- Have tried reinstalling Firefox several times
- Firefox Safe Mode is even worse, it is unusable, drawing only tiny pieces of the window or nothing at all
- Disabling Hardware acceleration for Firefox has the same effect as Safe Mode
- Although I think a virus is highly unlikely, I've run a full scan anyway with nothing found
- No other applications have this issue
More info:
- Windows 10 Professional is running inside the latest version of Parallels Desktop
- Connected to a 4K 32" monitor running at 100% scaling
- Changing scaling removes border but as soon as I resize once, white border reappears and I cannot resize
- Just tried disconnecting external display and running on laptop screen at various different resolutions, still no luck
Running inside a VM seems like the main point of difference - However I would have thought disabling hardware acceleration in Firefox would make that less relevant (instead, Firefox loses its mind with it off...).
It sounds very similar to this issue https://support.mozilla.org/en-US/questions/1250398 which does not seem to have any resolution. I've had this issue for a few months and was hoping perhaps the latest Windows update would have fixed it.
At the moment Firefox is unusable unfortunately.
Thanks in advance.
Modified by australisblue
All Replies (3)
hi, can you see if https://bugzilla.mozilla.org/show_bug.cgi?id=1524515#c9 is applicable to your situation as well?
philipp said
hi, can you see if https://bugzilla.mozilla.org/show_bug.cgi?id=1524515#c9 is applicable to your situation as well?
Wow.. this is a pretty obscure issue! I went and had a look in the registry at the AccentColor value that was set. Mine had feffb662 set as the value (alpha value of fe rather than ff). I'll note that I NEVER set this manually through the registry, only through the Windows colour settings quite some time ago (I am assuming around/exactly the time Firefox stopped working?). I remember turning on the setting to enable the accent colour to affect the title bar as well at the same time. The key is here: HKEY_CURRENT_USER\Software\Microsoft\Windows\DWM for anyone with the same issue.
Interestingly I went back into the settings, selected a different colour and back again and it updated the value in the registry to ffffb662. I restarted Firefox and it appears to now be behaving. Safe Mode also appears to work properly too.
It seems odd that the alpha value would be set to "fe" rather than "ff" in the registry. The thread you link to says the reason is because users have set the AccentColor value manually through the registry and not included an alpha value and so they won't be addressing the bug as only a small percentage of users would ever do this.. Clearly this is not true for all cases as I certainly did not change the registry value directly (why would I hunt down the value and work out the hex colour I wanted rather than just clicking the colour I want in the settings??). No one else has access to this machine either. It also looks as though it could potentially be any alpha value other than ff but needs testing.
I will test this properly tomorrow when I'm plugged into external displays but so far things look promising, thank you!
This seems to now work fine on external 4K monitors as well. Any alpha value other than ff causes it to break again if the option to show the accent on the title bar and borders is enabled.
To be clear, at no point previously did I hack a colour hex value directly into the registry. I recall going and selecting a custom shade of blue from the colour picker dialog in the personalise section of the settings and also enable the colour to be shown on the title bar.
While typing this, I remembered I had backed up the VM just after installing Windows 10 originally, I went and found that backup and booted it up to have a look. It appears as though the only thing I had done other that install Windows before backing it up was install Firefox.
At that point the accent colour still appears to be the default blue, I went in an had a look in the registry and the value is set as fed77800 .. strangely the same fe alpha value is there. Firefox works ok with it, until I enable to show the accent colour on "Title bars and windows borders". Perhaps modifying the default blue colour and saving it kept the original alpha value as well? (I can't see a way to set (or see) the alpha value in the colour picker window).
I think bug 1524515 should be reopened as clearly there is some scenario other than hacking the value directly into the registry that results in non ff alpha values appear in AccentColor.
Thank you philipp for realising this was the same as the bug you linked too.