Virtual machine dies instantly when unplugging external thunderbolt display

[smayoo]

This never happened before, I only noticed it after last update to VirtualBox 5.1.26 r117224. If I have a virtual machine window on an external thunderbolt display, it dies instantly (crashes without a sound or any kind of alert) when I unplug the thunderbolt cable from my Apple MacBookPro. Maybe it has nothing to do with external display, but with something else I use over that Thunderbolt link (ethernet connection, usb keyboard and mouse, external hard drive in a thunderbolt dock). But it definitely didn't happen before. Host computer is Apple MacBookPro 15" non-retina Mid 2012 (MacBookPro 9,1) with 16 GB RAM, 480 GB SanDisk SDSSDXPS480G, Nvidia GT650M, running Mac OS X 10.11.6. Guest machine is MS Windows XP SP3, 3GB RAM.

[Socratis]

Replying to smayoo:

Maybe it has nothing to do with external display, ...in a thunderbolt dock.

I cannot reproduce the problem with an external display over the Thunderbolt port (Thunderbolt -> DVI -> Apple Studio 17"). The worst case scenarion is that WinXP goes on full-display in another space in the main monitor, and goes back to its own space in the second monitor as soon as I replug the Thunderbolt cable:

• Host: OSX 10.11.6
• VirtualBox: 5.1.26 r117224 (Qt5.6.2), 5.2.0_BETA1 r117406 (Qt5.6.2)
• Guest: WinXP SP3

I left on purpose the "dock" part of your description. Since there are more that one things going on, could you limit it to what actually crashes the guest? And is it just the guest or everything VirtualBox* including the VirtualBox Manager?

[smayoo]

Crash report from window server

[smayoo]

Crash report from window server

[smayoo]

system console log grep on "virtualbox"

[smayoo]

Grrr... I wrote a detailed reply, but it got destroyed when I uploaded the attachments. :-[ The crash report is accidentally uploaded twice, but I can't delete the extra copy. The guest window crash is 100% repeatable (virtualbox manager window is unaffected, and after the crash, it reports the virtual machine as "aborted"), regardless of what else is connected or disconnected to the thunderbolt dock. So - it seems that the problem stays with the display itself. Also, guest crashes both ways - when I DISconnect the display, but also when I connect it. Only difference is that on DISconnection, the crash is instanteneous, and on connection the guest window lingers for a second and then crashes. Attaching a Mac OS Window Server crash log (the latest one, there's one for every attempt I made), and a Console Log excerpt (grep virtualbox).

[aeichner]

Your crash reporti ndicates an audio related crash. Please check if the latest test build fixes your problem. It contains a fix for an audio crash which was not yet fixed in 5.1.26.

[smayoo]

Thanks, it's downloading. What if I run into some other (more severe) problems? Can I just install the "official" version back over it?

[aeichner]

Sure installing the old version will work just fine. The testbuild is from the stable branch just containing additional bugfixes which will go into the next maintenance release, so the chance of regressions is very low (although not 0).

[smayoo]

The latest test build does indeed fix the problem. Thank you!

[Frank Mehnert]

Thanks for the feedback! It makes indeed some sense that your thunderbolt problem was actually audio-related.