I have Windows 7 as the host OS, VirtualBox 5.0.2 and Ubuntu 14.04 as a guest OS.
Right after I install Ubuntu the window resize works correctly, but I can't use 'copy-paste' and 'shared folders' functionality. As I knew from the Internet, in order to enable needed functions I have to use 'VirtualBox Guest Additions'.
I tried to install this from the menu (Devices->Insert Guest Additions CD image) and via the Terminal. Anyway, after the Guest Additions were installed I've got 'copy-paste' and 'shared folders' functions working, but the window resizing is now broken.
Could you, please, help me with this issue?
Solution:
Hm, the problem solved... unexpectedly: I reinstalled the guest OS, rebooted it, installed the Guest Additions from the menu and installed the system updates, that appeared in the unity menu (without the system reboot between the Additions and updates installation), and then rebooted the system. That helped - the 'window resize', 'copy-paste' and 'shared folders' functions are currently working simultaneously. Profit!