virtualbox.org

Hello.
Just updated from 4.x version to 5.0.8.
Host: win 8 x64.
Guest: win 7 x32.
Guest Additions installed.
Tried with 3D/2D acceleration enabled/disabled.

The issue is that guest OS has lost ability to display in 1920 on 1080 in 32-bit depth color. Before today's update everything was normal.
Needed resolution with color depth just missing from the list of all modes supported by VirtualBox Graphic Adapter.

Install the Guest Additions (in the guest). If you continue to assert that the GAs are already installed, then post a VM log file: With the VM fully shut down, right click it in GUI. Select "Show Log" and save "VBox.log" (ONLY) to a zip file. Attach the zip here.

I disabled 2D/3D acceleration before got logs and reinstalled GA.

I don't see anything wrong in the logs, except that you only ran for a couple of minutes, and the hi res 32bit mode didn't appear until you started shutting down.

The "needed resolution" may be missing from the list because Windows thinks you are already using that resolution. So, I would suggest explicitly selecting any other available display mode, then fully shut down the VM, then see if on a restart the mode you want becomes available.

mpack,
You was right. I just selected low resolution with 32-bit color depth and restarted VM. On the next start, VM automatically selected correct hi resolution with 32-bit color depth.
Where I can leave bug report?

I'm not yet convinced there was a bug. There may simply have been a change in the emulated hardware.

I just upgraded VirtualBox to latest version. Before the update everything was working fine.
Give me your criteria of “bug” please, if you have any objections.

A bug is any feature which does not work as intended by the software engineer. Windows failing to adapt to a change is not a VirtualBox bug. I have seen Windows get confused in exactly the same way on physical hardware, which is why I know what to do to fix it. You will note that you made no change to VirtualBox between the non-working and working states.