If Minecraft crashes, VirtualBox doesn't close and remains running in the background. This is a huge issue, especially regarding performance, as most users won't actually know it's still running (or worse still, know how to close it, since the only way to do so is through Task Manager or any similar method.)

I always knew this existed, but I don’t really know how I should fix this

This would make much sense as to why my computer gets a BSOD when Minecraft crashes. I haven't had Minecraft crash since I lowered the Max RAM usage

I always knew this existed, but I don’t really know how I should fix this

Runtime.getRuntime().exec("taskkill /F /IM VboxHeadless.exe")

I always knew this existed, but I don’t really know how I should fix this

Runtime.getRuntime().exec("taskkill /F /IM VboxHeadless.exe")

Doesn’t work on Linux or Mac.

If Minecraft crashes, VirtualBox doesn't close and remains running in the background. This is a huge issue, especially regarding performance, as most users won't actually know it's still running (or worse still, know how to close it, since the only way to do so is through Task Manager or any similar method.)

In the qemu branch I implemented something for this, when the game crashes and prints the crash report I hook into it and shut the VM down

I always knew this existed, but I don’t really know how I should fix this

Runtime.getRuntime().exec("taskkill /F /IM VboxHeadless.exe")

Doesn’t work on Linux or Mac.

On Linux and Mac you have to do this command: (@Delta2Force)
kill $(ps aux | grep '[V]BoxHeadless' | awk '{print $2}')