For several Updates of MacOS Copy & Paste stopped working in Terminal for the Editor in Midnight Commander. Since then i was searching for bringing it back since i work often with this editor. Now i found a method:

If you disable Mouse Reporting (View/Allow Mouse Reporting, ⌘R), mouse events will not be captured regardless of whether the application supports mouse or not, and you will be able to select and copy text via ⌘C & ⌘V. After that simply enable Mouse Reporting via ⌘R.

Source: http://apple.stackexchange.com/questions/188161/why-is-is-not-possible-mark-text-in-my-terminal-window-anymore