I installed Revit 2013 using the Serial # and Product Key given to me, but when I open the program, it says "License Unavailable. Revit Autodesk 2013 is in viewer mode" in which I cannot save files that I create. How do I get to the full version that I installed?
Are you using Standalone or network licensing? Did you try to activate the software and if so, was there any error messages? A little bit more information would help.