Ubuntu 18.04 in Windows 10 Pro host intermittently hangs when using Firefox

[Wittgenrock]

After having pleasant experiences with 17.10 and Virtualbox, I decided to use the same setup for my new computer, only this time with 18.10. It has gone pretty painlessly, but as the title indicates, the virtual machine will sometimes totally hang up. I can mouse over it, try to click in windows, press keyboard buttons, etc., but nothing happens. I am eventually forced to close the virtual machine, losing whatever unsaved stuff I have on there. This never happened when I was running 17.10 on my old computer.

I have tried fiddling with most of the knobs that Virtualbox puts at my disposal: 3D acceleration, RAM, VRAM, CPU, virtualization, disabling USB... the only thing that seems to matter at all is whether I am running Firefox inside the virtual machine or not. I have as of yet not seen a crash as long as I don't start Firefox, but whenever Firefox is running, a crash has so far always happened.

The crash sometimes happens after coming back from hibernation, but just as often it happens after having not 'focused' on the virtual machine for a minute or two (I run dual screens with the virtual machine on one of the screens).

I run i3 window manager (which I also did with 17.10).

Linux kernel version: 4.15.0-23-generic
Computer: Lenovo P50
Processor: Intel(R) Core(TM) i7-7700HQ CPU @ 2.80 GHz
Installed RAM: 16.0 GB
Windows 10 Pro build: 17134.1
Both host and guest are 64-bit.
Video card:
Quadro M1200
Driver version 388.16
Virtualbox version: 5.2.12 r122591

Current virtualbox settings for the guest (as mentioned, these have been fiddled with to little effect):
8 MB RAM
2 CPUs
100% execution cap
64 MB video memory
1 monitor
3D accel. enabled
Guest Firefox version: 60.0.2
Guest additions version: 5.2.12

I have also attached a log of the latest crash.

Please let me know if there are any more information that can be useful to clear this up!

[socratis]

00:00:05.108913 GUI:  Map mini-toolbar for window #0 to screen 1 of 2
00:00:05.108952 GUI:  Resize mini-toolbar for window #0 to 2560x1440
00:00:07.659586 GUI: UIMachineLogicFullscreen: Additions-state actual-change event, rebuild multi-screen layout

Could you try a less pixel-intensive setup? Something like a 1280x1024 windowed?

00:00:06.703766 VRamSize <integer> = 0x0000000004000000 (67 108 864, 64 MB)

You could take that to 128 MB, it's not like you don't have enough RAM available.

00:00:05.210063 File system of 'C:\Program Files\Oracle\VirtualBox\VBoxGuestAdditions.iso' (DVD) is ntfs

Always eject your Guest Additions (GAs) CD after you're done installing the GAs.

VirtualBox VM 5.2.12 r122591 win.amd64 (May  9 2018 10:42:46) release log
00:00:42.241105 VMMDev: Guest Additions information report: Version 5.2.10 r121806 '5.2.10_Ubuntu'
00:00:46.857104 VMMDev: Guest Log: 00:00:00.000189 main Executable: /opt/VBoxGuestAdditions-5.2.12/sbin/VBoxService

And we come to the "juicy" part. You are running VirtualBox 5.2.12 on your host, and you seem to have a mix of 1) the 5.2.10 forked Ubuntu GAs, 2) the 5.2.12 GAs. I don't know how you managed such a feat. I would re-install the GAs in the guest, and pay special attention to the output, in case of something not going right.

[Wittgenrock]

I honestly don't know how I managed to do that either! It has been fixed now though, and the problem persists. I tried all your suggestions, to no avail.

However, I think I have managed to dig deeper: It is not firefox by itself that triggers it, it's a specific combination of 1) Having Discord running in one of the tabs and 2) turning *off* my bluetooth headphones while the virtual machine does not have focus.

There seem to be some edge cases that avoids this - for example if I close and open firefox it seems to not happen. But in general, this is what triggers it.

What this means is unclear to me, but perhaps it has to do with Discord requiring access to the sound in some way?

I have uploaded a couple of more logs, in the hopes they can help in some way.

[socratis]

but perhaps it has to do with Discord requiring access to the sound in some way?

What "some way"? It's a voice-over-IP application, of course it requires access to the sound. And if you pull the sound options under its feet, it's going to freak out.

Please verify if it does the same thing on your host; Discord and Bluetooth as the chosen option, with the Bluetooth audio suddenly disappearing.

[Wittgenrock]

If "freaking out" means freezing the whole computer because it has no way of channeling sound, I'd say our little Discord is quite the drama queen!

However, the host version seems to handle it well, nothing happens at all when I run Discord in my host Firefox and turn off the bluetooth headphones.