Slitherine

I am trying to start Multiplayer and receive the popup message:
single player mode seems to work ok. I've looked around however I cannot find the so called launcher.

The main game has been updated (ahead of the Blitz-Krieg launch later today. I'm updating now.
That is probably why you get the multiplayer message, you can only multiplay with one specific game version.
The launcher is the main menu, at least in the Slitherine version. I think the Steam version is supposed to update automatically.

You can manually update it from the link below:
http://ftp.us.matrixgames.com/pub/Order ... p-v296.zip

Yes, using Steam. It has apparently updated and everything is working now.