Windows 8 guest additions 'no longer' work. "host delete" doesn't work, can't logon.

[Panther]

My guest additions no longer work. When windows 8 boots, I get a corporate popup banner that I can click on 'OK' to. Then I get the default windows 8 splash screen, (where you normally would use the "host Delete" keys to get prompted to logon. Those keystrokes don't work. None of the vm's menu options work either (like send crtl,alt, del to the vm). If I RDP to the vm and uninstall 'Guest additions' the vm will function as expected. This all started about 2 weeks ago, when I RDP'd into this vm, from home (via citrix). I'm assuming that process corrupted some files. I've since upgrade virtualbox from 4.3.30 to 5.0.4. reinstalled Guest additions and I have the same problem.

[Frank Mehnert]

Please reopen if still relevant with VBox 5.0.14. In that case please attach a VBox.log file from such a VM session.