Ionic v4: “Ionic cordova run -l” won't start my app

I’ve created an fresh ionic app a few days ago and worked on it perfectly fine until now.

Today I tried to start the development server: ionic cordova run -l but then I got this error message:

No target specified for emulator. Deploying to undefined simulator
Device type “com.apple.CoreSimulator.SimDeviceType.undefined” could not be found.
An error occurred while running subprocess cordova.

Logging currently available devices( ionic cordova run --list ) gives me this output:

Available ios devices:
Available ios virtual devices:

It is empty. None devices are available. Not for ios and neither for android.

Ionic version: 4.12.0

Cordova version: 9.0.0

What can I do to start my app properly again?