A code editor launch error

Question

When I tried to launch an external code editor in my browser it read the folowing:
TYPE ERROR: ARGUMENT 1 PASSED TO APP\HTTP\CONTROLLERS\EDXCONTROLLER::GETUSER() MUST BE AN INSTANCE OF APP\COURSE, NULL GIVEN, CALLED IN /DATA/LUMEN/APP/HTTP/CONTROLLERS/EDXCONTROLLER.PHP ON LINE 130
What does this mean and how can I solve it so that a code editor is launched?

Answer 1

Looks like an error in the php code

Answer 2

So, is it the problem in the course itself?

Answer 3

Do you have a username in this editor.
If yes what is it

Answer 4

Mandira