Main window content fully transparent

Just confirming, same here.
It happens quite randomly,
cannot reproduce at will.
Any ways to debug?

Status changed to 'Confirmed' because the bug affects multiple users.

This happens consistently in my installation. It makes GIMP impossible to use. Please let me know if I can provide any info that will help debug the issue.

Seems to be a compiz problem. Once the display is "infected," quitting from gimp and restarting it doesn't change anything. The main window resizes if I open a file, but the resized window remains completely transparent. Logging out and then back in "fixes" it. I'm running Ubuntu 14.04 with the unity interface.

If using nvidia graphics then possibly this is related to compiz bug #1072206

https://bugs.launchpad.net/ubuntu/+source/compiz/+bug/1072206/comments/8 fixed this for me

This is happening for me as well, as of a couple of months ago on Ubuntu 16.04

If it helps, usually after the computer has been on for many days without reboot.

Machine is a MacBook Pro.

I hit the transparent main image window issue in gimp again today after not having seen it for a long while.

Though I'm running 16.04 now, this issue goes back to Ubuntu 12.04 - at least - for me. I 'believe' the bug and proposed fix in compiz the nvidia folks ran down mid 2015 - and referenced in this thread - greatly reduced how often I see windowing issues and the severity thereof. In any case I've seen issue much less often over the past couple years.

Random info...

- Today I downloaded and installed the "CompizConfig Settings Manager" using the Ubuntu Software installer. Scrolling down there was a section called "Effects" where I deselected Animations as others herein suggested. Gimp has been working fine since. (Immediately turning the animation effects back on did not bring the gimp transparent image issue back...)

- Prior to turning off the compiz animation effects, my usual work around of starting gimp passing two images was working OK. Namely: 'gimp tinyBogusTransparentWindow.jpg myRealImage.jpg' The second image window shows up OK. You can also open multiple images via a right click in the transparent window to get image windows you can see.

- I too run with many windows up. Often 30-40 - mostly xterm windows. Like others the problem usually shows up only after having been running for a long time - 19 days this time. Reboots, log out & in fixes the issue.

- I also usually see other effects once compiz is messed up though they are less dramatic then with gimp. The cursor sometimes doesn't show up as it should in the firefox search window when firefox starts. Sometimes an extra click in a window is needed for window focus to shift.

- When I see the issue with a transparent window in gimp, I can sometimes get a first image window I can see if I just try starting gimp repeatedly - which hints a race condition.

-Intel® Core™ i3-4130 in-built graphics. Two physical displays.

I'll update should I see issues again now that I have the compiz animation effects off.

I have it with Java, Firefox, Remmina, Wine, Terminal, etc. Lately most often with the TortoiseHG's rejected chunks merge window. I on average ~10 windows open at a time. It doesn't matter if I recently rebooted or not. Both pop-ups and main windows. Sometimes fully transparent, other times it renders initially and then never again.

Now trying with Compiz "Animations" off to see if it makes a difference.

I'm having this too. Just disabling the animations plugin in ccsm doesn't solve the issue, but I have not tried to logout/login again. It was just an "on-the-fly" test. My Gimp opens with a 50% chance of having a transparent main window.

Maybe a special case because of hardware, but I encountered a semi-transparent GUI today.

The main window is mostly transparent as well as each dock except for titles and menus, which are correctly dark grey. I state "mostly" transparent because everything visible through the transparent regions is a moderately brighter color. The brushes all have transparent backgrounds, cyan symbols, a magenta lower-right arrow to select other brushes, and a solid green hover background. The color picker colors are only visible if the window behind is dark, and parts of the color ranges go full magenta as I choose colors.

NUC11 with a transplanted Dell XPS hard drive (did not reformat, just apt upgrade and installed nvidia driver 495)
Nvidia RTX 2060 + Iris Xe; monitor plugged into dGPU
10-bit color (set in xorg.conf.d and confirmed in /var/log and via screen test)
Ubuntu 21.10, GNOME 40.4.0, X11 (was Wayland on the XPS), 5.13.0-28-generic
GIMP 2.10.24 via apt (not flatpak)

There's no compiz on my machine, but I installed the settings-manager to double check if the solutions above work. As expected, animations is not even an installed module, so I removed the settings-manager. I also disabled GNOME extensions in case those had side effects.

Because of the color artifacts (especially the magenta at the ends of each color channel) and how this affects the UI (not related to color intent or color space), I suspect the 10-bit color is the source of the unwanted behavior, but I don't have a good explanation. (Although, I suspect I am not the first person to use a 10-bit monitor and dGPU with GIMP.)

To exonerate the GPU, monitor, kernel, GTK, etc.: Darktable, VLC, RawTherapee, and Inkscape have no issues and can display 10-bit and 8-bit gradient comparisons successfully.

Switching back to Wayland fixed the GUI (for #11 only; I can't speak for the rest of the thread). To do this, I had to add nvidia-drm.modeset=1 to the assignment GRUB_CMDLINE_LINUX_DEFAULT in /etc/default/grub, then run sudo update-grub and reboot.

Sorry to spam this thread. While GIMP loads with a normal GUI, it appears Wayland is not yet a valid solution after all. I seem to have a misconfigured system. Now, Nvidia X Server Settings has a completely empty GUI. Videos do not play in VLC. "llvmpipe" is now my graphics card. I'm probably using 8-bpp color again. If I successfully get Wayland working with 10-bit color channels, I can update if the same color issue occurs as with Xorg.