Cannot open MindNode file attached to note

What I did:
Attached a MindNode mind map file to an existing note.

What happened:
Neither clicking on attachment thumbnail nor selecting Open from context menu opens MindNode.

What I expected:
Opening attachments works with other applications (Project 365 [MS project clone], Excel, PDFs, Numbers). I expected the MindNode file to open.

Things that might be helpful to know (Agenda version, OS and model, etc):

Confirmed all of what said . Using Agenda 10.0.3 on macOS 10.15.5

It seems that Mindnode use a folder for their documents. We don’t yet support this, I’m afraid. It’s something we will try to add at some point. For now you would have to zip the file to attach it, but of course, then it wouldn’t be easy to preview.

Thanks for looking into it!