I just downloaded and installed the .NET API. I am working in WinForms VS 2010 with the .NET Framework 4.0. I installed the 'createsend-dotnet.dll' and ran into the following error on runtim:
Could not load file or assembly 'cs, Version=18.104.22.168, Culture=neutral, PublicKeyToken=null' or one of its dependencies. The system cannot find the file specified.
The createsend-dotnet.dll properties has all the correct information the error message says it needs.