After installing Guest Additions on my new Ubuntu GNOME 17.04 64bit VM system and rebooting it doesn't seem to start GNOME and hangs on this screen with cursor blinking:
i.imgur_com/rOSzlHN.png
If I uninstall Guest Additions through console it works again, but redrawing of graphics when changing window size is pretty choppy and slow, and of course I don't have the benefits of Guest Additions like shared clipboard.
I gave the VM 3 GB or RAM, 128 MB of video memory and enabled 3D Acceleration.
My regular Ubuntu 16.04 LTS VM with the same specs works fine.
The host is Windows 10 64bit. Virtualbox version is 5.1.22 r115126.