Hi @Rux ,
If you are using docker-compose, here’s what did the trick for me:
List the running containers:
docker-compose ps
Use this command with the n8n container name from previous step:
docker exec -u node -it n8n user-management:reset
Stop and restart docker.
Go to your n8n server. you’ll be presented with a signup screen. Create the owner account.
Don’t forget your credentials 
.
Hope this helps.