Have problem with basic sudo command line update???

Could someone please tell me why my Ubuntu Server 16 LTS will not update from the command line? When I type 'sudo apt-get update' my distro err's out. Below is the image I captured from my VM within VirtualBox.

Thank you very much for any and all help to this newbie ;-) BTW, this is all started when I was attempting to install the Guest Additions...

Mike

linux1.png

Attached Images

• linux1.png (21.7 KB)