The code looks good.

Just make sure you actually pass the $transferOptions to the 7th argument of the Session.SynchronizeDirectories:
https://winscp.net/eng/docs/library_session_synchronizedirectories and
https://winscp.net/eng/docs/faq_library_parameters

If this does not help, show us your complete code and attach a session log file.

Hi,

First, thank you so much for an amazing piece of software. Much appreciated.

I have a PowerShell script that leverages the WinSCP .NET assembly and works well.
I am Synchronizing the local files to match the FTP files.

I would like to update the script to sync only a single file in the remote directory. I'm trying to use the below Transfer Option to do this, but no matter what i try in there, I can't get any mask to work. Likely my syntax is off. I looked everywhere for an example that used .NET and filemask and was unable to find one.

$transferOptions.FileMask = "This is a file.csv"


Thanks so much!