在.Net 4框架中编译的应用程序将无法在Server 2012上运行

I compiled my application to use .NET Framework 4 because I need this to work on XP and Server 2003 that does not support .NET Framework 4.5. The issue is it now runs fine on the XP and 2003 servers but not on my Server 2012. Server 2012 has .NET 4.5 and from what I have read .NET 4.5 is backwards compatible with .Net 4I compiled my application to use .NET Framework