Windows 10 Host reboots upon start of Ubuntu Guest

[InfiniteSeries]

I downloaded and installed the Windows VirtualBox 6.0.4 platform package and created a VM for Linux Mint (32-bit). After starting the VM, I tried to get it to load the .iso file, and the host Windows system rebooted. I see no error in the last line of the VBoxHardening.log. I uploaded the last third of the file because it was larger than the 128KiB maximum. Also added the zip file. Windows 10 Version 1703 (OS Build 15063.1506)

[socratis]

and the host Windows system rebooted

Is this reproducible, does it happen every time, or was it a one of?

I uploaded the last third of the file because it was larger than the 128KiB maximum. Also added the zip file.

I removed the partial log, it's of no use. You did good and attached the whole thing ZIPPED.

[InfiniteSeries]

I have tried this many times. Here are the steps:

1. Open VirtualBox Manager
2. Create a new VM with the following paramters:
   1. Type: Linux
   2. Version: Ubuntu (32-bit)
   3. Memory size: 2048 MB
   4. Create a virtual hard disk now
   5. Hard disk file type: VDI
   6. Storage on physical hard disk: Fixed size of 20 GB.
3. Start the VM
4. Select start-up disk:
   1. Click on the folder icon next to the drop-down box that says, "Empty"
   2. Locate and select the previously downloaded (and checksum'd) linuxmint-18.3-cinnamon-32bit.iso file.
   3. Click Start.
5. After a few seconds, my host system reboots.

I have tried this with several 32-bit builds of Linux Mint, including 18, 18.3, and 19.
I have also tried this with Fedora-Workstation 29 (32-bit). [With version: Fedora (32-bit)]
I think this must be a configuration issue on my end, but I don't know where to look. I don't know if it matters, but I noticed that when I tried to use an existing virtual hard disk file from a Linux Mint VM set up earlier (which rebooted the host when started) for a new VM, when I start the (new) VM, it does not ask for a boot iso file. The host just reboots.
Thank you for your assistance with this.

[socratis]

That is really weird... But, can you completely uninstall all 3rd party, system-wide modifying software, like Symantec?

3178.29e4:     FileDescription: Symantec CMC Firewall SysPlant

Other than that, I don't have anything more to help me diagnose what's going on in your setup...