Cannot resize guest window, auto-resize and seamless mode are greyed out [GuestAddition is installed]
Host: Fedora 24, Guest: Win8.1
After installing guest OS, and installing GuestAdditions, I am unable to resize guest window.
It's size is fixed, 1024x768. In the View menu intem Seamless mode and Auto resize guest display are both disabled (greyed out).
Earlier everything was fine on my machine, it worked as it expected. But one day it went wrong. I uninstall and reinstall VBox, but the issue is still present. Then I made a clean Fedora 24 install on this machine, but the issue is still present. I've remove my GPU and used my motherboard integrated GPU but the issue is still present. In this machine I am unable to use VBox, because it's screen is too small, and unable to resize.