Client cannot connect to SMP server

Hi All

I installed .net 4.6 on SMP server.

After install it and restart server. It show error below. All agent cannot connect to server

  <![CDATA[Policy request failed: The remote web server is down or not responding properly, cannot determine SMP server version or SMP server version is not compatible. (0x80042D24)]]>

Could you please help?

Thanks