Re: Error
                You have different versions of 
In VS, the easiest to is to use NuGet package:
https://winscp.net/eng/docs/library_install#nuget
You definitely should not rely on the installed version (in
        WinSCP.exe, WinSCP.com (the problem 2) and WinSCPnet.dll (the problem 3)
In VS, the easiest to is to use NuGet package:
https://winscp.net/eng/docs/library_install#nuget
You definitely should not rely on the installed version (in
Program Files) of the WinSCP.exe. Your application should include/deploy its own copy.