Re: 5.2.2 beta error when running.
That's correct. You need to use the same version of the assembly as WinSCP.
The version of C:\Program Files (x86)\WinSCP\winscp.exe (5.1.5.0) does not match version of this assembly C:\Users\jeff.clay\Documents\Visual Studio 2010\Projects\VOIP-no-service\VOIP\bin\Release\WinSCPnet.DLL (5.2.2.0). You can disable this check using Session.DisableVersionCheck (not recommended).