I am working on a trailhead challenge to create a Partners community and self-register a community member.  I created the Customers community and added a new registration successfully, but when I try to register a Partners community member, or add another Customers community member I get an error that says "Your request cannot be processed at this time.  The site administrator has been alerted."  Any suggestions on how to get around this?  Thanks.

I am working on a trailhead challenge to create a Partners community and self-register a community member.  I created the Customers community and added a new registration successfully, but when I try to register a Partners community member, or add another Customers community member I get an error that says "Your request cannot be processed at this time.  The site administrator has been alerted."  Any suggestions on how to get around this?  Thanks.

I think there is a glitch in the in structions on the first activity. # 6 says, "Check the box for Launch New Custom Tab Wizard after saving this custom object."  However, you cannot check the box afterwards as the box disappears once you save the custom object and you cannot go back and edit it. Please help if you know how I can undo this or if there is a place I can go back and check the box. It is messing up the challenge and I cannot proceed without doing this step. Thanks!