Vbox won't open vm window - only title bar shows

[timbury]

Hello,

I have a new (full) installation of Slackware 14.2 on a Dell G5 laptop. I installed latest VirtualBox (Version 6.1.6 r137129 (Qt5.6.1)) and have tried to create a new vm with iso files for PopOS and Ubuntu 20.04 amd64 guests with the same result for all. The iso boots, the preview window shows the installer waiting for input, but the vm window opens for a few seconds then closes to what seems to be a titlebar. It cannot be opened. If I double-click on the right end of the bar, I get a dialog offering various methods of closing the machine.

I used to be a release engineer and was something of an expert with VMware, OSes, etc. But that was 20 years ago. I'm a bit rusty these days. I've checked permissions on files, etc. At first, I did everything as root. Then I made a vmuser account to manage the VMs. No difference. I've never encountered this issue before. I'm probably doing something incredibly stupid but damned if I can find it. I wasn't able to find this exact issue posted, forgive me if I missed it. I uploaded 2 files - a log file for Ubuntu 20.04 and a screenshot. I appreciate any & all help. Thanks.

UPDATE: I downloaded and imported a Solaris 11 VM from Oracle's VirtualBox site with the same results both keeping their settings and adjusting some setting for my machine. I couldn't upload the Solaris log, it's too big. If you want to see it let me know & I'll make it available.

[scottgus1]

One thing I see is you have a scale factor of 3, or 300%, on the guest window. I can only achieve 2, or 200% on my 6.1.6. So something has gone wrong somewhere. The guest is booting from the CD-ROM, and appears to be running well in the background. Power it off then change the Display scale factor to 1.

[timbury]

Thanks, scottgus1 ! I started out with the scale set to 1, since that is the default, and got the same result. I should have mentioned, the native resolution on this display is 4k UHD - 3840x2160. With the scale set to 1, it's a mighty tiny window.

[fth0]

I can only achieve 2, or 200% on my 6.1.6. So something has gone wrong somewhere.

I don't think so. On my Notebook with a 1920x1080 resolution, the limit is 200%, but on my iMac with a 5120x2880 resolution, the limit is 300%. This is consistent between the VirtualBox Manager and the VM window's View menu. I'd guess that on high resolution displays the limit is deliberately higher.

[scottgus1]

Ah, interesting, fth0! scaling the scale... Ok, so that's not it.

timbury, could you please reboot the host so no Virtualbox processes are running, then please zip and post the guest's .vbox file, using the forum's Upload Attachment tab.

[timbury]

Hi, scottgus1. Not sure what processes you're concerned about, but a couple virtualbox processes start at boot time, so rebooting won't ensure a 100% clean environment. I've shut down the VMs and VBox itself. This site won't allow uploading of vbox files (idk why) so I've added a little text at the end of the file name.

[scottgus1]

There is something weird about the window position tag in the .vbox file:

<ExtraDataItem name="GUI/LastNormalWindowPosition" value="0,366,213,21837"/>

Let's try resetting that. Issue these command in a terminal window:

vboxmanage setextradata "vUbuntu 20.04" "GUI/LastNormalWindowPosition"
vboxmanage setextradata global "GUI/LastWindowPosition"

Try the guest again.

[timbury]

Thanks for your patience and continued help, scottgus1. Unfortunately, that didn't work. After following your instructions, the same number was still in the file. I even tried closing the VM & app and manually editing the file. I changed the '21837' to '637' (sounded reasonable), but no change in behavior.

[scottgus1]

After following your instructions, the same number was still in the file.

This probably means the command wasn't entered properly or the vm name is not right. Was there an error message? If the commands completed, the whole "GUI/LastNormalWindowPosition" and "GUI/LastWindowPosition" keys are supposed to disappear completely. Did you re-open the .vbox file before restarting the guest? Restarting the guest would put the keys back in again with the numbers reflecting a default start point, not the old numbers.

[timbury]

I'm certain the commands were entered exactly as directed. There were no error messages, or messages of any kind. Each command was accepted and I was returned to the prompt. I can't recall if I peeked at the file before restarting the guest. It's likely I did. I'm not sure what effect this would have. I did manually edit the file to change that one value. After restarting VBox & the vm, then shutting it all down again, I saw the original, unusual value had been rewritten to the file.

[timbury]

Okay...

I closed VBox. I issued (again) the 2 commands. I immediately checked the file: the line with the wacky value is gone. I open VBox & check the file: all is well. I open the vm, which exhibits the same broken behavior, & check the file: all is well. I close the vm ("Power off the machine.") and the line is back with the wacky value returned. Why is VBox writing this wacky value and what is it supposed to represent? I, perhaps wrongly, assume they are the coordinates of the corners of the vm window.

[fth0]

I, perhaps wrongly, assume they are the coordinates of the corners of the vm window.

Close. The values describe the VM window's coordinates with "x,y,width,height". If you want to also check the result of the 2nd VBoxManage command, look for ~/.config/VirtualBox/VirtualBox.xml (depending on your Linux distribution, the file path may be different).

[timbury]

Thank you, fth0, for disabusing me of my mistaken notion. The host OS is Slackware 14.2 and the path is as you said. The following is the line of concern:

Code: Select all

<ExtraDataItem name="GUI/LastWindowPosition" value="311,53,690,360"/> 

which seems rational to me.

Not wanting to simply drop VBox for VMware or an alternate product, I've downloaded the source code to see if I can find where these values originate and why the one bizarre value for height is written. I appreciate all your help.

[fth0]

I've downloaded the source code to see if I can find where these values originate and why the one bizarre value for height is written.

Please tell us what you discover. If you point me to the right direction, I can have a look, too. But note that I'm no VirtualBox developer (like most Volunteers and Moderators in these forums).

[timbury]

After downloading and looking through the source code, I found a couple of places where the values for this window seem to be discovered or configured, as the case may be. As I think I said, I'm not a C++ guy (wish I was). There is something that looks like a function definition in UIExtraDataDefs.cpp and it's header file, UIExtraDataDefs.h (...?.../src/VBox/Frontends/VirtualBox/src/extradata/ The first dir or 2 might be mine, I don't remember.). Some relevant code can also be found in UIExtraDataManager.cpp in the same directory. I've already trashed this, so I don't have the ability to look up paths, etc. I did make some notes, which is what I'm working from here. I'm done. I don't have the time to troubleshoot this right now, though I'd be willing to do so later. For now, I axed Slackware in favor of Q4OS (Debian 10). Have another Vbox issue but I'll start a different topic for that. This was from Vbox 6.1.6, but I'm now using 6.1.8. For the sake of those with similar issues, I'll put some of the relevant code points here. These are starting points... grep for these and look at the code surrounding these lines.

From UIExtraDataDefs.h:

Code: Select all

/** Prefix used by composite extra-data keys, which holds normal machine-window geometry per screen-index. */
SHARED_LIBRARY_STUFF extern const char GUI_LastNormalWindowPosition;

From UIExtraDataDefs.cpp:

Code: Select all

/* Virtual Machine: */
...
const char *UIExtraDataDefs::GUI_LastNormalWindowPosition = "GUI/LastNormalWindowPosition";

From UIExtraDataManager.cpp (around line 1939):

Code: Select all

<< GUI_LastNormalWindowPosition << GUI_LastScaleWindowPosition

From UIExtraDataManager.cpp (around line 3075):

Code: Select all

From QRect UIExtraDataManager::machineWindowGeometry(UIVisualStateType visualStateType, ulong uScreenIndex, const QUuid SuID)  <--- The 'S' in the final term, SuID is in question - can't rad my notes.
(
    /* Choose corresponding key: */
    QString strKey;
    switch (visualStateType)
    {
        case UIVisualStateType_Normal: strKey = extraDataKeyPerScreen (GUI_LastNormalWindowPosition, uScreenIndex); break;
        case UIVisualStateType_Scale: strKey = extraDataKeyPerScreen (GUI_LastNormalWindowPosition, uScreenIndex); break;
        default: AssertFailedReturn(QRect());
    }

See also around lines 3109 and 3127. Again, this is from my notes and may not be completely accurate. It may give you an idea where to start looking. There is some relevant code in a file for a WinXP guest that hard-codes the four values but I didn't try that. It is at ...src/VBox/main/testcase/ovf-winhost-audio-nodisks/WinXP.ovf. Thanks again for the help!