If you are opening multiple registration pages at the same time, they are expected to fail. You must open one page, fill the form, submit it and only then you can open another.
1- Did anyone else had this problem besides you?
2- Have you attempted to clear your browser's cache?
3- Which browser are you using?
I have tested with Internet Explorer, Mozilla Firefox and Google Chrome and all of them succeeded. There were no errors at all.
Nabble staff. We never ask for passwords.