The Session.PutFileToDirectory return TransferEventArgs, not TransferOperationResult.
https://winscp.net/eng/docs/library_session_putfiletodirectory

There's no need to check "success" after Session.PutFileToDirectory, as it would throw an exception on error:
https://winscp.net/eng/docs/library_session_putfiletodirectory#remarks

Hi,
I'm new to this forum, and first to say, I'm not a .NET developer.
I use the assembly as addin in our ERP system development (Dynamics NAV).

My code looks about this, I hope you can read it. NAV has different notation than .net languages

WinSCPTransferResults is WinSCP.TransferOperationResult.
Success is a boolean.

This code results in an error like this (translated from german):

Error on call of WinSCP.TransferEventArgs.get_IsSuccess with the following message:
The type of at least one argument not matching the parameter type of the method.

the error occurs on the second line, where I try to get the success info.

If I use the method WinSCPSession.PutFiles instead, it works.

Has anybody an idea what I'm doing wrong here?

Greetings.