I've been trying to get Guest Additions running on Debian 9 in VirtualBox.
I tried to install Guest Additions via VirtualBox, via Direct download from virtualbox.org and via apt.
Everytime fail with Kernel headers. But I installed them as shown in several tutorials. (first I tried
linux-headers-$(uname -r) later
The last thing I tried was working on Debian 8 where I had the same problem
apt-get install virtualbox-guest-dkms virtualbox-guest-x11 linux-headers-$(uname -r)
The additions seemed to be installed. I didn't get an error when I tried to add shared folders. Before I got a message everytime saying that the GuestAdditions are not installed.
But after reboot I still have no fullscreen 16:9 display and there are no shared folders mounted
What's the problem? What can I do to fix this problem?