Odd problem but I am running Tixati on Debian 12 in an Xfce environment, using Gigolo to mount a Windows share to which I gave the windows account full administrator access (that's overkill, I know).

When I start the torrent download Tixati creates the folder structure over on the windows share but then stops writing and gives me this error:

"error opening: Operation not supported (95)" after downloading 16.3K of my 1.94M e-book.

If I change the settings to download to a folder on the Linux VM then it works fine.

So, what am I missing in order to be able to write the torrent from this Linux VM to that Windows fileshare? Is it a permissions issue? Some package I'm missing?

"Operation not supported" sounds like an issue with the share protocol in that it does not permit (support) a certain I/O operation Tixati tries to do. I guess it's not an issue with the client, i.e. how you mount the share on Linux, but with the protocol being too limited.

Just a guess: did you enable preallocation in Tixati settings? Try turning it off or choosing Full PreWrite

Create a mount point on the Linux workstation and mount the CIFS / SMB share there. It will work then.