Alt+Tab no longer working for some clients after upgrade to 5.1.18

[Hamms]

My standard workflow for a couple years now has involved using a Debian 8 64-bit VM with Guest Additions on my Windows 8.1 64-bit host and essentially treating it as a terminal emulator, then using my host machine for everything else. I typically have the VM fullscreened and use alt+tab extensively for switching between it and my host.

After I upgraded VirtualBox on Friday to 5.1.18, I am no longer able to alt+tab away from my VM, whether it fullscreened, windowed, or in seamless mode. I can confirm that the host key is working fine and that the problem is not that the keyboard is being unexpectedly captured. Even more bizarre, I also encounter the problem on my 32-bit Debian VM and my Ubuntu 16.04 64-bit VM, but not on my Windows 7 (32-bit) or 10 (64-bit) VMs.

Any ideas?

[socratis]

I typically have the VM fullscreened and use alt+tab extensively for switching between it and my host.

I don't remember that ever working. Are you sure you didn't have to do "HostKey, Alt-Tab", i.e. first switch the focus from Debian and then send the Alt-Tab sequence to the host? From host to guest, yes, but from guest to host, I don't see it.

I upgraded VirtualBox on Friday to 5.1.18

From what? What happens if you go back to the last used VirtualBox version?


PS. For future reference, you should completely shut down the VM before grabbing the VBox.log. Then ZIP it before attaching it to your response.

[Hamms]

Yes, naturally I would hit the hostkey first then alt+tab.

I did just complete a downgrade back to 5.0.36, and that appears to have resolved my issue. That being said, I'd still like to figure out what was going wrong so I don't have to remain on this version of VB indefinitely.

PS.

Noted; my apologies for skimming the instructions.

[socratis]

Yes, naturally I would hit the hostkey first then alt+tab.

And that's not working with 5.1.18? Or you didn't have to use the HostKey in 5.0.36?

I'd still like to figure out what was going wrong so I don't have to remain on this version of VB indefinitely.

They changed the capturing code, in response to the bugs introduced in 5.1.x, in response to the upgrade to the underline Qt framework. You might have to remain in the 5.0.x for a while.

PS. The behavior that you were reporting, *was* buggy. You *are* supposed to press the HostKey first to redirect the keyboard from the guest to the host. Or vice versa.

[Hamms]

I believe you're misunderstanding. Of course I've always had to use the hostkey to stop capturing keyboard input. That behaviour did not change; when in windowed mode, I could confirm that the hostkey capturing was still working as expected.

The thing that changed in 5.1.18 is that _after_ I hit the hostkey and stopped capturing input, alt+tab would not then work. Even though my input was no longer being captured.

[Hamms]

Update; downgrading to 5.0.36 _appeared_ to fix my issue, but it's returned.

[Hamms]

Downgrading to 4.3.40 seems to have resolved the error, but still does not explain its nature.

[socratis]

still does not explain its nature.

I believe I did give it a shot. I might be off in the versions, so let me try and correct my previous statement:

They changed the capturing code, in response to the bugs introduced in 5.1.x 5.x.x, in response to the upgrade to the underline Qt framework. You might have to remain in the 5.0.x 4.3.x for a while.

BTW, one of the changes in 5.1.20 was:

• GUI: fixed non-literal shortcuts if the keyboard is not captured (5.1.10 regression; Windows hosts only)