What does your configuration on the rest of the page look like? Do you have subnets specified? I don't really see how that page could generate that error. Maybe log out clear browser cookies and temp files then log back in.
Adam R MS | CISSP, CISM, VCP, MCITP, CCNP, ITILv3, CMNO If this was helpful click the Kudo button below If my reply solved your issue, please mark it as a solution.