Modern versions of Mac OS do not allow users to create home directories with spaces in them. However we have seen cases where our own staff have managed to create home directories with spaces.
This then means that Iguana won’t start. This video shows how to diagnose the issue:
How do you fix it? One approach could be to just create a new user account and the copy the data from your home directory into the new account. You would need to be confident with dealing with file permissions.