I can't edit the texture orientation I'm new on blender and I'm making a cars track for Assetto Corsa.
I'm about to finish the track. I was finishing the walls and a problem became:
I can't see the walls texture on the UV/Image editor. I select all the face which I want to see in the UV/image editor, I press U>Reset and then U>follow active quads and I don't see anything on the V/Image editor, so I can't rotate the texture.
I looks like this, it's kinda weird:

I've seen that with U>Smart UV project it automatically rotates but only with some faces. Any suggestions?

I'd like to ask for something else: When I select a cube face from the array blender selects that face of all the cubes on the array. How can I select individual cubes of the array to delete them individually? 

I leave my .blend, so anyone can check everything needed.
Thanks in advance!
UV Map doesn't show when the Render Result is selected in the UV/Image Editor. So, please, try clicking on the X button. As shown below:



For deleting face of individual cubes you have to first Apply the Array Modifier. However, note, that it will convert all cubes to single mesh, so they won't be affected by the Curve Modifier after that.