I am already part of a prediction community. I would like to create another player with the same e-mail address.
Earlier, you could register several times in a prediction community with one and only one login. This is not possible anymore. Hence it is not possible to create two players in the same community. The change was motivated by technical settings.
Nevertheless, nearly everybody has got an own e-mail address or can create one quickly and for free, e.g. at Google Mail.
The administrator is able to create new members in the admin area in the "Manage members" section and can submit predictions retroactively for them.
By the way: You can of course register in different prediction communities with one login.