Authentication failed due to a user credentials mismatch after installing August 2017 Updates on an NPS Server. After patching and rebooting NPS server for RADIUS authentication, clients could no longer connect to wireless network.
The following error in the NPS event log:
Microsoft has provided a workaround to this issue which is to create a DWORD in the registry to disable a client certificate check. This can be implemented by opening regedit.exe on your NPS server and going to the following location:
In the above key create a DWORD called DisableEndEntityClientCertCheck and set the value of it to 0 and restart your NPS server.
Thanks guys, link to source below.