VirtualBox 4.3.36 Windows Guest Video fail

[JohnLangford]

I'm running windows 10 guest on an Ubuntu 14.04.4 LTS. I upgraded to VirtualBox 4.3.36 and installed the appropriate guest additions, but am now seeing the video fail.

Initially, everything seems fine with the guest taking the full 1920x1080 screen. After running for up to hours, then the guest complains and resizes down to a (very cramped) 1024x768 for unclear reasons. The relevant bit in the logs is:

00:55:25.234067 VBVA_INFO_SCREEN: [0] @0,0 0x0, line 0x0, BPP 0, flags 0x2
00:55:25.234090 Display::handleDisplayResize(): uScreenId = 0, pvVRAM=0000000000000000 w=1920 h=1080 bpp=0 cbLine=0x0, flags=0x2
00:55:25.234095 UIFrameBuffer::RequestResize: Screen=0, Format=0, BitsPerPixel=0, BytesPerLine=0, Size=1920x1080, Sending to async-handler..
00:55:25.234163 UIFrameBufferQImage::resizeEvent: Format=0, BitsPerPixel=0, BytesPerLine=0, Size=1920x1080
00:55:25.234173 UIFrameBufferQImage::resizeEvent: Resizing to FALLBACK buffer due to format is invalid..
00:55:27.380044 UIMachineLogicFullscreen: Guest-screen count changed.
00:55:27.380767 UIMultiScreenLayout::update: GUI/AutomountGuestScreens is disabled.
00:55:27.381040 UIMachineLogic: Guest-screen count changed.

Any idea what's going on? All my attempts to change the video mode, etc... have no effect in fixing this problem.

[socratis]

1. Start the VM. Not from a saved or suspended state. Clean start.
2. Take the steps required to generate/observe the error.
3. Shut down the VM. Not suspended, not paused. Shut down.
4. Right-click on the VM in the VirtualBox Manager. Select "Show Log..."
5. Save it (just the first log), ZIP it and attach it in your response (see the "Upload attachment" at the bottom of the form).

[JohnLangford]

Log from clean start and complete shut down exhibiting the problem is attached.

-John

[socratis]

VirtualBox VM 4.3.36_Ubuntu r105129 linux.amd64 (Jan 27 2016 12:09:06) release log

It looks like you're using Ubuntu's fork version of VirtualBox. You can either ask in their forums for help, or completely remove their version and install the official version from the Downloads section of VirtualBox (https://www.virtualbox.org/wiki/Downloads).

00:00:00.165952 Installed Extension Packs:
00:00:00.165962   VNC (Version: 4.3.36 r105129; VRDE Module: VBoxVNC)
00:00:00.165965   Oracle VM VirtualBox Extension Pack (Version: 5.1.0 r108711; VRDE Module: VBoxVRDP unusable ...

...yet somehow you've managed to install two different versions of the Extension Pack. You should only have matching versions of the ExtPack. Thankfully 5.1.0 gets rejected in your case.

[JohnLangford]

Thanks. The unclean removal was apparently why I could not install 5.1. I have 5.1.2 installed and am now seeing a similar problem at 1152x864. I'll try to debug a bit more and make a separate post if necessary.