I was going to move this to the bug forum, but I cannot duplicate the problem. The map shows up on the clipboard for both DX11 and DX9 versions of the game.
By the way, the maps can be up to 2048x2048 (4096x4096 might work) and will display just fine.
If it is not showing up on your clipboard, then I would need to see a DXDIAG output to see what it is about your computer which is not allowing it to show up.