Open the file as super-user:
sudo nano -c /etc/apt/sources.list.d/virtualbox.list
and make sure you are on line 1(you can see the line number in the terminal like this. Then, add the #
at the beginning of line 1. When that is done, press Ctrl+X. At the prompt, press y and then Enter
Then run sudo apt-get update
.
Just note that:
By commenting/removing the erroneous line the software won't be installed (if not already) or won't be updated/upgraded if that's what you try. Of which I suggest you to check where is that line coming from (which software requires it) and do the proper modifications as required in order to everything run fine.
Source.
cat /etc/apt/sources.list.d/virtualbox.list
. Cheers, Al – heynnema Oct 06 '16 at 16:54