Authentication Error only when in full screen

[BikerSco]

Hi Guys,

So I have a strange issue. I have an install of CentOS 7 running on VirtualBox (V 5.1.18) on my mac (OS X El Capitan). When I open the virtual machine in full screen mode I get a window which asks for a username and password but I am unable to click in the box to type anything in. The only way to get rid of this window is to come out of full screen mode and it disappears, I then go back in to full screen mode and I get the CentOS 7 login window with text already entered in to the password field as if I had been typing in it while trying to type in to the authentication required window which wouldn't disapeer. Once it's gone I can use CentOS 7 fine with no further issues.

Here is a screen shot of the window which appears. So this is only there for as long as I have the virtual machine open in full screen mode, as soon as I change to window mode it disappears.

<removed screenshot> as it won't let me post it as i'm a new member of the forum.

Cheating I know :

http://i.imgur.com/gyHylfn.png

[socratis]

Usually you would attach the picture here, since not a lot of people will go to a 3rd party site. But you shouldn't really post a 2673x1656, mostly black, 150 KB picture, when the message is just a short:

Authentication Required

Authentication is required to set the network
proxy used for downloading software

Password: ______________

Cancel      Authenticate

Now, are you sure you're starting the VM in full-screen and not resuming the VM? Or restoring it? Because this doesn't look like a startup screen login type or a password dialog. It looks to me like the "updater" is trying to check the network for any updates.

Moving to "Linux Guests" from "OSX Hosts".

[Perryg]

This is a CentOS 7 error and you need to fix it within the guest. Something in the network configuration is incorrect.