FortiEMS AD sync

Hello, 

I am facing a problem since I have updated our EMS server in 6.2.7 version.

The sync of our AD domain is not working, I have to restart the "FortiClient Endpoint Management Server Active Directory Service" to get it works a few time and then it stuck again.

Has anyone is facing the same issue ? How can I resolve this issue ? 

Best regards,

Sayf