AD Connect Stops Syncing

Question

This happens at random times of the day, but primarily, early in the morning; most recently 7:30AM, AD Connect will just stop attempting to sync. I am currently running Windows Server 2016 Datacenter. Ad Connect version 1.4.38.0. When I attempt to force a delta sync, I receive the error at the bottom. I have attempted to see if the process was held for some reason, but I can't find any instance. I have also tried to restart the process via the Services window, but that did not work either. The ADSyncScheduler says everything is fine. I only came into this environment a few weeks ago and am still learning how everything is setup. Not sure if its pertinent info, but the server itself is rebooted everyday at 1:30AM.

Start-ADSyncSyncCycle : System.InvalidOperationException: Azure AD Connect scheduler is unable to start a new sync
cycle because Azure AD Connect wizard is open. Please close the wizard if it is not in use.
   at Microsoft.MetadirectoryServices.Scheduler.Scheduler.StartSyncCycle(String overridePolicy, Boolean
interactiveMode)
   at SchedulerUtils.StartSyncCycle(SchedulerUtils* , Char* policyType, Int32 interactiveMode, Char** errorString)
At line:1 char:1
+ Start-ADSyncSyncCycle -Policytype Delta
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : WriteError: (Microsoft.Ident...ADSyncSyncCycle:StartADSyncSyncCycle) [Start-ADSyncSyncCy
   cle], InvalidOperationException
    + FullyQualifiedErrorId : System.InvalidOperationException: Azure AD Connect scheduler is unable to start a new sy
   nc cycle because Azure AD Connect wizard is open. Please close the wizard if it is not in use.
       at Microsoft.MetadirectoryServices.Scheduler.Scheduler.StartSyncCycle(String overridePolicy, Boolean interactiv
   eMode)
       at SchedulerUtils.StartSyncCycle(SchedulerUtils* , Char* policyType, Int32 interactiveMode, Char** errorString)
   ,Microsoft.IdentityManagement.PowerShell.Cmdlet.StartADSyncSyncCycle

Answer 1

@Shaun Healy From the query, you mentioned the current version of Azure AD Connect is 1.4.38.0 which is a very old version, below snippet copied from https://learn.microsoft.com/en-us/azure/active-directory/hybrid/reference-connect-version-history#:~:text=and%20permissions.-,Retiring%20Azure%20AD%20Connect%201.x%20versions,-Important where 1.x version are retired.

Would recommend you to upgrade the Azure AD Connect to the latest version 2.1.20.0 - https://www.microsoft.com/en-us/download/details.aspx?id=47594 If you have any further further questions, feel free to post back, if required we can connect offline to discuss further on this issue. You can reach me at by sending an email on azcommunity [at] microsoft [dot] com referencing this issue with a subject line "ATTN:Givary" and we can connect over teams to discuss the same.