[Bug]: Cannot choose an ISO from the filesystem to boot from when trying to boot a VM with no operating system

[ArrayBolt3]

Version

7.2.2

Host OS Type

Linux

Host OS name + version

Ubuntu 24.04 LTS

Host Architecture

x86

Guest OS Type

Linux

Guest Architecture

x86

Guest OS name + version

Not applicable

Component

GUI

What happened?

If I try to boot a virtual machine with no operating system, a popup appears that states:

The virtual machine failed to boot. That might be caused by a missing operating system or misconfigured boot order. Mounting an operating system install DVD might solve this problem. Selecting an ISO file will attempt to mount it after the dialog is closed.

This then provides a "DVD:" combo box for selecting an ISO file from which to boot the VM. Previously, if I selected the "Other..." option in this combo box, a file selector window would appear, allowing me to find and choose the ISO to boot. However, in VirtualBox 7.2.2, clicking the "Other..." option silently fails; I see the combo box display "Other..." as selected very briefly, then it vanishes and the "DVD:" combo box is left blank.

A brief video showing the issue:

vbox-other-failure-2025-09-27_23.42.27.mp4

How can we reproduce this?

1. Launch Oracle VirtualBox Manager from the system's application menu.
2. Click the "New" button to create a new VM.
3. Set the "VM Name" field to ubuntu-test.
4. Do NOT select an ISO image.
5. Expand "Specify virtual hardware", and set "Base Memory" to "4096 MB".
6. Set "Number of CPUs" to "2".
7. Click "Finish".
8. Double-click "ubuntu-test".
9. When the "VirtualBoxVM" popup appears prompting you to select a disk image to boot from, click the drop-down arrow on the "DVD:" combo box, then click "Other...".

Did you upload all of your necessary log files, screenshots, etc.?

• Yes, I've uploaded all pertinent files to this issue.

[baserkan]

Hello. I cannot reproduce this and I am not surprised. That "Other" option is forwarded to QFileDialog which tries to open system's file manager. I guess in your case something goes wrong and file manager cannot be found. On my Debian 12 plasma desktop Dolphin file manager opens up. Do you have a file manager installed?

[baserkan]

@ArrayBolt3 Also could you please start the VM via CLI with VirtualBoxVM --startvm [vm_name] ? that may print some useful information on the command line.

[ArrayBolt3]

@baserkan Just tried that, unfortunately I did not see any output on the command line when I clicked the "Other..." button. Upon closing the VM window, one line of output appeared:

┌─╴aaron@kf-m2g5:~
└─╴$ VirtualBoxVM --startvm ubuntu-test
Qt WARNING: QObject::disconnect: Unexpected nullptr parameter

I doubt that's relevant though.

Worthy of note, the "Other..." button in other parts of VirtualBox works, for instance when choosing the ISO media to load into a virtual disc drive from within the VM settings dialog.