64-bit C# applications can only run on .NET Framework 2.0 and above. When installing your development environment, you must ensure that either the 64-bit version of the .NET SDK or the full Visual Studio 2005 Professional package or later version is installed on your 64-bit Windows host.
You must add a reference to the 64-bit version of the .NET API (Platform.Symphony.Soam.Net_64.dll) in your Visual Studio application project files; see the 64-bit Symphony DE samples for details.
Since 64-bit C# applications are only supported on .NET framework 2.0 and above, you must use Visual Studio 2005 or later version to build your 64-bit applications.
When compiling the samples for a 64-bit environment using Visual Studio, you must use the solution files suffixed with 64.<version>.sln, or 64_<version>.sln where <version> is 2005 or later.