Gatekeeper warning when opening LumaSpace

If you downloaded LumaSpace from the App Store, this shouldn't happen. Delete the app and re-download it from the store.

Downloaded from the website?

macOS blocks apps from outside the App Store by default. Here's how to open it:

1. Find LumaSpace in your Applications folder.
2. Right-click (or Control-click) the app icon.
3. Click Open from the menu.
4. A dialog pops up. Click Open again.

You only need to do this once. After that, macOS remembers and opens it normally.

Alternative method

Go to System Settings > Privacy & Security. Scroll down and you'll see a message about LumaSpace being blocked. Click Open Anyway.

Don't disable Gatekeeper entirely. It's there for good reason.