Error handling: I have not been on my computer with Ubuntu for a long time, why does the screen look like a code?

Just out of curiosity, and I can not do anything on my computer at this time either. When I write a command, the message "Error: the screen is not specified" appears and I feel it is important to take it into account.

Basically, I only get the code and it does not show up. White text on black background.

This is running Ubuntu 14.04.4