Xenmobile Certificate based authentication--Unable to push VPN policy to iOS device.

Error : In the software inventory for the device we can see the error “Could not create mobilecofig ” Server logs 2017-02-24T10:35:05.236+0100 | | INFO | http-nio-10080-exec-72 | com.sparus.nps.apple.push.ApplePush | Installing profile /cfg/VPNtest on device 522. 2017-02-24T10:35:05.298+0100 |...