can't add a NPS RADIUS client 2

Hi all,

I am having the exact same issue as per the old thread with title: can't add a NPS RADIUS client

I indeed have Windows Server 2008 r2 Standard edition, however inside the resolution it is stated that :

"Generally, we can configure a maximum of 50 RADIUS clients and a maximum of 2 remote RADIUS server groups."

So my question is how is the 50 RADIUS clients number calculated? I currently have zero and I am still getting this error message.

Thanks