This copy of Malbec is incomplete
Its engine is missing. Download Malbec again; your games and settings stay.
What happened
Malbec’s engine (Wine and DXMT) comes inside the app, and this copy doesn’t have it. That happens when a download was cut short or files were removed from the app.
The fix
Click Download Malbec and replace the app in Applications with the new download. Your games, settings and sign-ins stay: they live in a separate folder.
When to write to us
If a fresh download says the same, write to us.
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.