[Noob] Can't add new user - internal server error 500

I just set up a brand new yunohost server and configured CA certificate with lets encrypt. Tried adding first user and got this error:

(127.0.0.1 is not my ip, if that means anything)

All I want to do is learn more about this stuff and familiarize myself with the functionality available in the basic yunohost package.

Any help is appreciated!