Cannot register a new user

[ugultopu]

Using a92dc52.

Installed CDash with docker:

sudo docker-compose pull cdash
sudo docker-compose up -d
sudo docker-compose run --rm cdash install configure

Went to localhost:8080 and CDash is up:

Try to register a new user:

Getting a server error:

Is this expected or is this a bug? How can I get this working?