Crash when 'un-pausing' paused VM on Win10 host

[ueli]

I usually have 1 or 2 guests open on a Win10 host. When I'm not using the host system, I suspend or hibernate it. In addition, I manually pause a VM when not using it, in order to save host resources.

Sometimes I get crashes:

• I manually want to resume a paused VM. Crash! I then do a normal shutdown of the other VM as guest user (start button). The second VM crashes too. Conclusion: It's probably not a problem of a single VM instance, but rather of some component common to all guests.

• I suspend/resume the Windows host. On resume, I immediately get a VM crash, presumable because vbox does an implicit pause/resume of a VM.

These things happen with some probability. I can't reproduce it reliably. On vbox 6.0.12 the probability was so low that I didn't really mind. With 6.0.14 and 6.0.16 the probability seemed much higher, so I didn't use them. Now I have switched to 6.1.2 r135662 (Qt5.6.2) and I get it quite often.

I have already described my problems in ​https://forums.virtualbox.org/viewtopic.php?f=6&t=96538

I'm reporting now a case that seems to be typical. Here is what I did:

---

1. Start Ubuntu guest.
2. Start WinXP guest.
3. Manually pause the Ubuntu, while WinXP keeps running.
4. Put host (Win 10) asleep.
5. Wake up the host. On wakeup, I immediately get a message notifying me of a VM crash. It turns out that the WinXP guest is gone, the paused Ubuntu guest is still there.
6. I try to manually resume the paused Ubuntu, but it crashes immediately.

---

I attach logs of both VMs. The following lines in the logs may be of interest:

20:58:02.032649 !!! rtR3WinUnhandledXcptFilter caught an exception on thread 000000000000163c!!! (Log of Ubuntu guest)

18:34:20.151649 !!! rtR3WinUnhandledXcptFilter caught an exception on thread 0000000000002e00!!! (Log of WinXP guest)