I thank you for your response and your engagement!
I followed your advice and first changed the directory name for the VM folder to the standard VirtualBox VMs:
I am running Manjaro on a NVME drive on btrfs, which has the following volumes and partitions:
# <file system> <mount point> <type> <options> <dump> <pass>
UUID=5BCD-7D96 /boot/efi vfat defaults,umask=0077 0 2
UUID=7fa7979a-a0e0-476d-ae0e-53941ec65064 swap swap defaults 0 0
UUID=28f95c5e-1540-44e0-af83-1f58ee10a7d7 / btrfs subvol=/@,defaults,noatime,compress=zstd:3 0 0
UUID=28f95c5e-1540-44e0-af83-1f58ee10a7d7 /home btrfs subvol=/@home,defaults,noatime,compress=zstd:3 0 0
UUID=28f95c5e-1540-44e0-af83-1f58ee10a7d7 /var/cache btrfs subvol=/@cache,defaults,noatime,compress=zstd:3 0 0
UUID=28f95c5e-1540-44e0-af83-1f58ee10a7d7 /var/log btrfs subvol=/@log,defaults,compress=zstd:3 0 0
tmpfs /tmp tmpfs defaults,noatime,mode=1777 0 0
UUID=5b578c12-7401-47a4-857a-c9cfac7ce47b /home/jaqueline/VirtualBox\040VMs ext4 defaults 0 0
The *.vdi VMs are located on the ext4 partition in the last line of the fstab above. Nothing else is on that ext4 partition.
This partition is mounted to the directory VirtualBox VMs, which is located at /home/jaqueline/VirtualBox VMs.
I have removed all references to any previous VMs on this new computer.
I just have moved one of the old but previously working VMs to the ext4 partition:
/Win7-Test.vdi without its *.vbox file.
Then I followed your advice (but without the point “set OS to Arch Linux” – where should I select this???)
I selected the existing VDI as the “existing harddisk” and click finish.
Immediately the VBox-Manager freezes!
VBox-Manager had created the new directory for this machine correctly. In the *.vbox file I get the uuid of the machine:
Machine uuid="{468dba2c-f153-41b2-9b5e-75732da22242}"
and of the harddisk / VM:
HardDisk uuid="{a4a5f509-2786-431f-9252-daac2621f784}"
And in the file /home/jaqueline/.config/VirtualBox/VBoxSVC.log I get:
00:01:00.821205 DCon01 Finished saving settings file "/home/jaqueline/VirtualBox VMs/Win-7/Win-7.vbox"
00:01:19.543814 main VirtualBox: object deletion starts
00:01:19.543866 main ERROR [COM]: aRC=VBOX_E_OBJECT_IN_USE (0x80bb000c) aIID={7d510820-a678-4730-a862-818dcd3fbed0} aComponent={MediumWrap} aText={Medium '/home/jaqueline/VirtualBox VMs/Win-7-Test/Win-7-Test.vdi' cannot be closed because it is still attached to 1 virtual machines}, preserve=false aResultDetail=0
00:01:19.544154 main HostDnsMonitor: shutting down ...
00:01:19.544243 main HostDnsMonitor: shut down
00:01:19.563973 Watcher ERROR [COM]: aRC=E_ACCESSDENIED (0x80070005) aIID={d644ad1e-c501-4fc7-9ab6-aa6d763bc540} aComponent={VirtualBoxWrap} aText={The object is not ready}, preserve=false aResultDetail=0
00:01:19.564006 main VirtualBox: object deleted
At the end, I get exactly, what I have observed in my first posting. Vbox is correctly installed and kernel module is fitting the my kernel version 6.12. VBox has read/write access to the VM directory on the ext4 drive. And I am using the conventional directory name for the VMs in the mount point.
VBox Manager freezes every time, when a new machine should be created or when an existing machine should be added.
If I could switch to kernel 5.15 without getting trouble, I would do it, just to try, whether the difficulties will persist.
Another idea which will not solve the problem, but could be of interest concerning the results:
As I am now using standard folder names for VBox, I have copied all the files from ./config/VirtualBox/ and the corresponding VMs from the drive of my old computer to my new one and then start VBox Manager just to see what happens:
Nothing! It just freezes as soon as I start the VBox Manager! Even the GUI will not become visible!
I have no clue, whats going on here.