Linux 32bits no longer starts

[Jialing]

Hi,

I have a Kubuntu 18.04 32bits guest created before. It worked fine until several days ago. However today when I tried to start it, it failed to start.
Virtual box version: Version 6.1.12 r139181 (Qt5.6.2)
Host:
Windows 10 pro.
HP Probook 430G6
Processor: Intel(R) Core (TM) i5-8265U CPU@1.60GHZ
Windows 10 Version 1909 (OS build 18363.959).

I searched this forum, and tried the following:
1. disable hyper-V in control panel
2. Enable Vt-x in BIOS
3. Display changed to VBOXVGA.
4. Disable memory integrity.
But the problem is still there.

Please see the attached log file.
Thanks!

[Martin]

What do you mean with "failed to start"?
The log shows the guest os starting and getting an IP address at 01:02

[Jialing]

Hi Martin,

Thanks for your reply.
The screen showed the text "Kubuntu 18.04", then blank out.

Regards,
Jialing

[fth0]

Set Settings > Display > Screen > Video Memory to 128 MB. If the problem persists, start the VM in headless mode to circumvent potential video problems during booting, and observe the preview in the VirtualBox Manager, where you can switch to normal mode later on (Machine > Show).

The Linux guest has the VirtualBox Guest Additions 5.2.8 (GA) installed that only know about the VBoxVGA graphics controller, and also don't know anything about VirtualBox 6.1.12. You should uninstall the GA as soon as possible. You could try and start the VM in headless mode, connect to it over the network, uninstall the GA, shut it down, and restart it in normal mode. Afterwards, you can install the GA matching your VirtualBox version and select the VMSVGA graphics controller.