Comment 7 for bug 1429086

Solved for me. I used "createsuperuser" on the console, but didn't provide an email-address there. To be honest, I thought it wasn't really needed at that stage :-) But mailman-core seems to reference the user by his/her email-address internally and so some api-calls failed. Since mailman-core answered with a 500-error imho this is something that mailman should fix on their side. So I added a bugreport for them to maybe be a bit more relaxed in such error-cases and not fail hard.
https://gitlab.com/mailman/mailman/issues/127

Solved here?