Symptom
If you disable TLS 1.0 and 1.1 support on ISE. PAC is not provisioned.
Error from ISE: Client requested TLSv1.0 or TLSv1.1 that is not allowed.
Conditions
Disable TLS 1.0 and TLS 1.1 support on ISE
Workaround
Re-enable TLS 1.0 and TLS 1.1
Further Problem Description
TLS 1.2 support for PAC provisioning purposes was added until 17.x
