500 Internal Server Error When enrolling device to Profile Manager

Hello,

We have a Mac mini Server with Sierra 10.12.1 installed,

Version of Server.app is 5.2

Is bound to Active Directory (have tried unbinding - re-binding)

Was having trouble with Open Directory, but used time machine and reverted to an earlier backup. Open Directory is there.

Currently have about 112 devices on Profile Manager, trying to add 6 more. This was all working fine about 4-5 weeks ago.

Something has gone wrong and I am not sure why. All existing devices (didn't test all) on the system can have apps installed to them just fine, I can also push out settings also.

Below is an entry from the device server log concerning my attempts to enroll devices to Profile Manager here.

This could be a permission error??

If anyone has any idea, please let me know.

Thanks.

0:: [6574] [2017/02/23 16:45:28.592] <IP OF DEVICE> Completed in 417ms | 500 Internal Server Error [https://myserver.domain.local/devicemanagement/api/device/auto_join_ota_service]

0:: [3489] [2017/02/23 16:59:24.144] do_dmx_get_scep_challenge_for_host: caught exception -[SCEPHelper getSCEPChallengeForHost:] (/Library/Caches/com.apple.xbs/Sources/RemoteDeviceManagement/RemoteDeviceManag ement-904.29/Compiled/Framework-Base/Support/SCEPHelper.m:89): "'((SCEPHELPER_GetSCEPChallenge(self.connection, hostname, hostnameCnt, &challenge, &challengeCnt)))' error 1"

0:: [3489] [2017/02/23 16:59:24.145] <IP OF DEVICE> EXCEPTION: 500 Internal Server Error - Could not retrieve SCEP challenge. at

#0 /Applications/Server.app/Contents/ServerRoot/usr/share/devicemgr/backend/php/ot a_service_common.php(196): DieInternalError('Could not retri...')

#1 /Applications/Server.app/Contents/ServerRoot/usr/share/devicemgr/backend/php/ot a_service_common.php(313): _generate_scep_profile(Array)

#2 /Applications/Server.app/Contents/ServerRoot/usr/share/devicemgr/backend/php/au to_join_ota_service.php(16): OTAServiceCommon()

#3 {main}