I recently installed Debian Jessie 8.2 using dvd-1 (that is debian-8.2.0-amd64-DVD-1.iso) on VirtualBox version 4.3.22 with gdm3 as the display manager and GNOME as the desktop environment. My host OS is Windows 7. It was working fine, until I tried to install Guest Additions with these instructions to try to enable full screen. Another major thing that I did before this error, was to edit the sources.list file (commented out the deb cdrom line) to solve an apt-get install error. Now, the full-screen functionality works fine, that is I can login successfully, and enter the Desktop, but every time I click on Activities on the top-left corner, and afterwards on any one of the icons in the left toolbar, it aborts with an application error that looks like this:
Could anyone please help me with this, its my first time on Debian, and I am new to Linux as well.