Permission problems with VirtualBox after editing fstab

Permission problems with VirtualBox after editing fstab

I tried to automount my storages but it didn't worked. I removed the drives from the fstab again and now I get this error message from VirtualBox:
one or more virtual hard disks are not currently accessible
This is the location of the vmdk:
/media/julian/Spiele/Wohnzimmer-PC/Wohnzimmer-PC.vmdk
When I try to start an old virtual machine I get this:
Fehlercode:
NS_ERROR_FAILURE (0x80004005)
Komponente:
Medium
Interface:
IMedium {29989373-b111-4654-8493-2e1176cba890}
This is my fstab now:
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
# / was on /dev/sda1 during installation
UUID=6c4d478a-685e-49db-b3a0-120c238eb075 /               ext4    errors=remount-ro 0       1
# swap was on /dev/sda5 during installation
UUID=ab098910-8d7b-4b4d-aca0-e788371e3167 none            swap    sw              0       0
I can fully access all storages with Nautilus.