When you come from a non-PEFNG install to one that has PEFNG installed, you change the nature of roles and access policies. The role that was in place before was probably sufficient for your use, but now that you have PEFNG installed, it is likely trying to redirect you to a Captive Portal page.
For example, the initial role of a AAA profile without PEFNG is "logon". This role when PEFNG installed is configured for Captive Portal.
Run show user to see what role the users are in
Run show rights <name-of-role> to see what policies are applied to the user now
If you want to allow the users full access (may be recommended until you determine how you want to use the roles/policies):
config t
aaa profile <name-of-AAA-profile>
initial-role authenticated
wr memory