Error : This scheme is referenced in a Domain

Hello

HP switch 1920

want to remove RADIUS servers (that are defined), getting this error

This scheme is referenced in a Domain

I want to remove the defined RADIUS and create new again.

Because facing Authentication problems , after implementing port security, AAA, when connecting client to the switch port.

PC gets connected on the DOMAIN / NETWORK, gets correct VLAN subnet IP (As defined in NPS/NAP server)

but it is in "Attempting to Authenticate" state.

And after 2 minutes PC disconnects from the network, and re authentication occurs this cycle goes on again and again.

Thanks

Regards