How long did you wait before terminating the process?
What Web browser do you use?
Did you have an Internet connection at the time while trying to start up the Creator?
Do xou use antivirus of any sort? Firewall?
Are you sure it says “waiting for player” and not “waiting for Ui”?
In my experience it sometimes takes a while to start. You could try to close the browser window and restart it from the tray icon.
Iirc “waiting for player” has something to do with connection problems, but @Benjamin and/or @Steve can tell you for sure.