Gray screen viewer, lose the terrain?

When I open the project I see only a gray screen but if I click in play I can see my terrain and walk. How can I fix this problem? (I think is problem of the camera) and also I can read "Isnormalized (dir)"

Somehow the camera got moved way out of the scene. Click on an object in the hierarchy, move the mouse pointer over the scene view, and press "F" to focus on the selected object.