The error was most likely due to the space in the username (possibly the length).
Most free forums, etc just need a working email address to register. If you are not conducting financial transactions, etc nobody will be checking that entered names are plausible, let alone legitimate (you can enter Peter Pan if you want). It may be against the terms of service to enter a false name, though.
user name - AlrikFassbauer
first name - Alrik
last name - Fassbauer
