Today, it seemed in my Ubuntu 14.04 VM (Kubuntu 14.04 host), there was an update for the Guest Additions to 4.3.12, and I was requested to install them from the Devices menu. I did this, but even though the Guest Additions installer ran completely OK (though it looks like it did a "non-kernel" installation), Guest Additions are not working properly and I don't get 3D graphics acceleration.
Is there any way to solve this problem with the latest version of Guest Additions?