XCode 8.1 shows same file side by side, no 'x' button to remove second window

Question

After a few months of not writing any iOS code I upgraded to XCode 8.1 and opened a project. Strangely I am seeing two windows (see pasted image below). Annoyingly these two screens move in sync, show the same file, etc, but one cannot be closed. There is no 'X' at the top to close the window. Has anyone run into this and how can I get rid of one of the screens?

Answer 1

Probably you activated the version editor without noticing it. To revert to the standard editor, hit the button on the top right corner of the window with a drawing showing lines justified to the left (right next to a button with two circles and another with arrows).

Alternatively go to the menu:

View -> Standard Editor -> Show Standard Editor

or hit the Command + Return keys.

That should do it.