Set up the store first
Then the game can start from it.
What happened
This game starts from its store, and that store isn’t set up in Malbec yet.
The fix
Click Set Up the Store. Malbec installs it, and you sign in on the store’s own window. Then press Play.
When to write to us
If setting up the store shows a different message, its page explains that one. Write to us if none of them helps.
Email support@malbec.app. For a diagnostics file, choose Help › Export Diagnostics… in Malbec and attach the zip it saves. It has no account details, and your home folder is masked.