I tried to re-install macOS on my MacBook Pro (Retina, 13-inch, Early 2015) via the internet (Command+Option+R). After 5 minutes and some progress the following was shown, what does it mean?
apple.com/support does not know this error code.
It looks like you need to reset your device's NVRAM. Check out Apple's documentation that explains how to do that: How to reset NVRAM on your Mac