Ok so i have used unity3d for now like 4 years and today my shadows stopped working, I have know clue why and i have not changed anything. You can see the shadows in the editor but not in game or in build. If anyone gots a answer for this then please share :)! Here is a pic with editor and light settings.
You should check you quality settings (Edit → Project Settings → Quality).
Make sure that the target platform(Green box) is set to the same level as the editor(gray Bar).