User Agent: Mozilla/5.0 (Windows NT 5.1; rv:36.0) Gecko/20100101 Firefox/36.0 Build ID: 20141103030205 Steps to reproduce: 1. Install Firebug 2. Open the attached demo 3. Inspect the page with Firebug 4. Move the mouse over Firebug's window, right-click it to open context menu, etc. Actual results: Some black boxes appear if OMTC is enabled. Expected results: They shouldn't appear. Note it's not a problem of Firebug. With Firebug it's always easy to reproduce, but in some occasions I have had the same problem with Firefox's devtools, or just page's scrollbars. Also note the boxes may not be black depending of the theme.

Not sure if this is the same as bug 1019909.

Could you open about:support and paste the "graphics" section, please. Did you test with OMTC disabled? (about:config>layers.offmainthreadcomposition.enabled=false)

(In reply to Loic from comment #4) > Could you open about:support and paste the "graphics" section, please. > Did you test with OMTC disabled? > (about:config>layers.offmainthreadcomposition.enabled=false) Yes, disabling OMTC it works fine. The bug only happens when it is enabled. Here is my graphics info: > Adapter Description NVIDIA GeForce 6150SE nForce 430 > Adapter Drivers nv4_disp > Adapter RAM Unknown > Device ID 0x03d0 > DirectWrite Enabled false (0.0.0.0) > Driver Date 1-31-2013 > Driver Version 6.14.13.783 > GPU #2 Active false > GPU Accelerated Windows 0/2 Basic (OMTC) Blocked for your graphics card because of unresolved driver issues. > Subsys ID 00000000 > Vendor ID 0x10de > WebGL Renderer Google Inc. -- ANGLE (NVIDIA GeForce 6150SE nForce 430 Direct3D9 vs_3_0 ps_3_0) > windowLayerManagerRemote true > AzureCanvasBackend skia > AzureContentBackend cairo > AzureFallbackCanvasBackend cairo > AzureSkiaAccelerated 0

I can also reproduce it on another PC (Win Vista): > Adapter Description Intel(R) G33/G31 Express Chipset Family > Adapter Drivers igdumd32 > Adapter RAM Unknown > Device ID 0x29c2 > Direct2D Enabled Blocked for your graphics driver version. > DirectWrite Enabled false (7.0.6002.23200) > Driver Date 2-11-2008 > Driver Version 7.14.10.1437 > GPU #2 Active false > GPU Accelerated Windows 0/1 Basic (OMTC) Blocked for your graphics driver version. Try updating your graphics driver to version 7.1500.1000.1666 or newer. > Vendor ID 0x8086 > WebGL Renderer Blocked for your graphics driver version. Try updating your graphics driver to version 7.1500.1000.1666 or newer. > windowLayerManagerRemote true > AzureCanvasBackend skia > AzureContentBackend cairo > AzureFallbackCanvasBackend cairo > AzureSkiaAccelerated 0

In your case, your drivers are not supported anymore. For the NVIDIA GeForce 6150SE nForce 430, the latest are 307.83 (2013.2.26): http://www.nvidia.com/download/driverResults.aspx/57493/en-us (these ones you have already) For the Intel(R) G33/G31 Express Chipset Family, the latest are 15.12.4.1666 (03/05/2009): https://downloadcenter.intel.com/Detail_Desc.aspx?DwnldID=17407&lang=eng But I don't think updating the Intel drivers will change anything, it's too old. Nical, do you have a better idea than disabling OMTC?

(In reply to Loic from comment #7) > In your case, your drivers are not supported anymore. By Firefox? Or by NVIDIA/Intel? > But I don't think updating the Intel drivers will change anything, it's too > old. Yes, I have just updated the Intel driver and the problem remains. Firefox now says > Adapter Description Intel(R) G33/G31 Express Chipset Family > Adapter Drivers igdumdx32 > Adapter RAM Unknown > Device ID 0x29c2 > Direct2D Enabled Blocked for your graphics driver version. > DirectWrite Enabled false (7.0.6002.23200) > Driver Date 2-26-2009 > Driver Version 7.15.10.1666 > GPU #2 Active false > GPU Accelerated Windows 0/1 Basic (OMTC) > Vendor ID 0x8086 > WebGL Renderer Google Inc. -- ANGLE (Intel(R) G33/G31 Express Chipset Family Direct3D9Ex vs_0_0 ps_2_0) > windowLayerManagerRemote true > AzureCanvasBackend skia > AzureContentBackend cairo > AzureFallbackCanvasBackend cairo > AzureSkiaAccelerated 0

I have tried it on a computer (Win 7) with better graphics: > Adapter Description AMD Radeon HD 6290 Graphics > Adapter Drivers aticfx64 aticfx64 aticfx64 aticfx32 aticfx32 aticfx32 atiumd64 atidxx64 atidxx64 atiumdag atidxx32 atidxx32 atiumdva atiumd6a atitmm64 > Adapter RAM 256 > Device ID 0x9807 > Direct2D Enabled Blocked for your graphics card because of unresolved driver issues. > DirectWrite Enabled false (6.2.9200.16571) > Driver Date 4-17-2014 > Driver Version 14.100.0.0 > GPU #2 Active false > GPU Accelerated Windows 1/1 Direct3D 11 (OMTC) > Subsys ID 05981025 > Vendor ID 0x1002 > WebGL Renderer Google Inc. -- ANGLE (AMD Radeon HD 6290 Graphics Direct3D9Ex vs_3_0 ps_3_0) > windowLayerManagerRemote true > AzureCanvasBackend skia > AzureContentBackend cairo > AzureFallbackCanvasBackend cairo > AzureSkiaAccelerated 0 And there is no problem. However, if I disable HWA, I can reproduce it. Now Firefox says > GPU Accelerated Windows 0/1 Basic (OMTC) Blocked for your graphics card because of unresolved driver issues.

Good: 2014-05-19 Bad: 2014-05-20 Pushlog: https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=41a54c8add09&tochange=cb9f34f73ebe Note those versions have OMTC disabled by default, so you must enable it manually to reproduce the bug.

Confirmed on Firefox 36. Why there're so many unconfirmed bugs that clearly DO happen? I remember this bug. It was very messy, involving corruption of UI elements. It was fixed by a random "new to Bugzilla" guy with GoogleChrome UA in bug 1151749. He's just my hero Just in case, I bisected using the testcase. Fix range: > https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=2f60ba22839a3beb8259c05171ffc51c5e05c750&tochange=caf25344f73e491409e16dff59e5599858c87e32