Created attachment 206751 [details] xvboxadd-install.log Kernel came in with a dist-upgrade this evening, March 3, 2016. I have dkms installed. When the kernel was installed and I rebooted, the VM window size was reset to 640x480 and cannot be resized. System Settings | Display Configuration also no longer has any screen resolutions to choose from; just 640x480. I re-installed VirtualBox Guest Additions 5.0.0 and this is the output: Verifying archive integrity... All good Uncompressing VirtualBox 5.0.0 Guest Additions for Linux........... VirtualBox Guest Additions installer Removing installed version 5.0.0 of VirtualBox Guest Additions... Removing existing VirtualBox DKMS kernel modules ...done. Removing existing VirtualBox non-DKMS kernel modules ...done. Copying additional modules ... Installing additional modules ... Removing existing VirtualBox DKMS kernel modules ...done. Removing existing VirtualBox non-DKMS kernel modules ...done. Building the VirtualBox Guest Additions kernel modules The headers for the current running kernel were not found. If the following module compilation fails then this could be the reason. Building the main Guest Additions module ...done. Building the shared folder support module ...fail! (Look at /var/log/vboxadd-install.log to find out what went wrong) Doing non-kernel setup of the Guest Additions ...done. Installing the Window System drivers Warning: unknown version of the X Window System installed. Not installing X Window System drivers. ...done. Installing graphics libraries and desktop services components ...done. Press Return to close this window...
Access to the existing Shared Folder also is no longer functional.
This 'bug' can likely be closed as not valid. When I launched my VM today, it informed me that there was a newer version of the Guest Addtions (5.0.16) which matches the version of VirtualBox I'm running. Downloaded and installed the updated version and rebooted the VM. Everything works (again) as it is supposed to.