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Rozplay's avatar
Rozplay
Copper Contributor
Sep 01, 2026

Taskbar goes dark black intermittently

Pretty sure this is a bug with Windows' MPO or graphical presentation model, but basically:

For the past few months my taskbar has 'randomly' been going dark black, usually with Chrome open. Upon moving the mouse or clicking the taskbar, it immediately reverts.

It's not a monitor and it's not a driver issue. This has also persisted across a fresh format and fresh driver installs.

Turning off "Show shadows under windows" seems  like it reduced the frequency, but it still happens even with that disabled.

I've been told that potentially, disabling HAGS might fix it - but that shouldn't be necessary in the first place.

 

What is going on with this?

community

2 Replies

  • Gask's avatar
    Gask
    Steel Contributor
    Sep 04, 2026

    MPO is a graphics optimization that lets different layers (like your Chrome window and the taskbar) be composed separately for better performance. But when two hardware-accelerated apps overlap—say, Chrome playing a video and sitting on top of the taskbar—the rendering queue can get tangled. This causes DWM to glitch, temporarily turning the taskbar black until you click or move the mouse to force a redraw.

  • Lennonui's avatar
    Lennonui
    Tin Contributor
    Sep 03, 2026

    Since your research led you to MPO, this is a direct way to address it. A blog post discussing a similar "window overlay bug" on Windows 11 25H2 specifically mentions that the issue is caused by an MPO or DWM rendering conflict and provides a registry fix.