00:00:01.653682 Guest OS type: 'Ubuntu_64'
...
00:00:01.698858 [/Devices/hpet/0/Config/] (level 4)
00:00:01.698859 ICH9 <integer> = 0x0000000000000001 (1)
Please do
not deviate from the defaults. The ICH9 chipset is experimental and only for OSX guests!
00:00:01.657171 File system of 'Z:\VBox\Buben.vdi' is unknown
What is "Z:\"? Internal? External? Network? And what filesystem is it?
00:00:01.591951 VRDP: TCP server listening on port 3389 (IPv4 and IPv6).
Do you need to have the RDP server enabled?
00:00:01.698976 VRamSize <integer> = 0x0000000001000000 (16 777 216, 16 MB)
You should max out the VRAM in the VM Settings, Display.
00:00:11.620641 VMMDev: Guest Additions information report: Version 5.2.8 r120774 '5.2.8_KernelUbuntu'
Not only are these older GAs, but they're not the official ones. Uninstall them and install the ones that came with VirtualBox. With the VM having the focus, go to the menu "Devices" » "Insert GAs CD image..." and follow the installation prompts. If you want to "control" the VM from the host, you'd better make sure they're on the same page...
VirtualBox VM 5.2.18 r124319 win.amd64 (Aug 14 2018 12:39:01) release log
00:00:11.620641 VMMDev: Guest Additions information report: Version 5.2.8 r120774 '5.2.8_KernelUbuntu'
00:00:18.598469 VMMDev: Guest Log: VBoxService 5.2.12 r122591 (verbosity: 0) linux.amd64 (May 9 2018 12:07:53) release log
You know why I used three different colors? Because you've created a multi-version setup! Different main program, different service, different GAs
(and forked ones actually). You got to clean it up, mainly by removing anything VirtualBox-related in the guest, and installing the GAs as their maker intended. See the previous point...