Synchronization state data is corrupt or otherwise invalid – Microsoft Dynamics 365 for Developers

If you get an Unhandled Exception in your mailbox profile alerts, but no real information, where it comes from, then this post will help you.

I got the following alert in my mailbox:

<params>
	<param type="0" otc="9606" oid="48d028d3-8c53-e811-9103-005056a26140">Mittermair, Michael</param>
	<param type="0" otc="9605" oid="9dd1ce55-e851-e811-9102-005056a26140">MailProfile</param>
</params>

<details>
	<detail key="servererrorcode">Exchange.server returned ErrorInvalidSyncStateData error.</detail>
	<detail key="servererrorhelplink">Microsoft.Crm.Asynchronous.EmailConnector.ErrorSource.ExchangeError:ErrorInvalidSyncStateData</detail>
</details>	1	NULL	BACKEND	ExchangeSyncUnknownACTIntegrationError	0	T:109
ActivityId: 8820ea97-0688-4cff-b9c7-b1fc8da070d6

<param type="0" otc="9606" oid="48d028d3-8c53-e811-9103-005056a26140">Mittermair, Michael</param>

<param type="0" otc="9605" oid="9dd1ce55-e851-e811-9102-005056a26140">MailProfile</param>

</params>

<detail key="servererrorcode">Exchange.server returned ErrorInvalidSyncStateData error.</detail>

<detail key="servererrorhelplink">Microsoft.Crm.Asynchronous.EmailConnector.ErrorSource.ExchangeError:ErrorInvalidSyncStateData</detail>

</details> 1 NULL BACKEND ExchangeSyncUnknownACTIntegrationError 0 T:109

ActivityId: 8820ea97-0688-4cff-b9c7-b1fc8da070d6

I enabled the tracing on the backend server and also checked the log in the database and found the following:

>Exception : Unhandled Exception: Microsoft.Exchange.WebServices.Data.ServiceResponseException: Synchronization state data is corrupt or otherwise invalid.    
at Microsoft.Exchange.WebServices.Data.ServiceResponse.InternalThrowIfNecessary()    
at Microsoft.Exchange.WebServices.Data.MultiResponseServiceRequest`1.EndExecute(IAsyncResult asyncResult)   
at Microsoft.Exchange.WebServices.Data.ExchangeService.EndSyncFolderHierarchy(IAsyncResult asyncResult)    
at Microsoft.Crm.Asynchronous.EmailConnector.MonitoredExchangeService.EndSyncFolderHierarchy(IAsyncResult asyncResult)    
at Microsoft.Crm.Asynchronous.EmailConnector.ExchangeSyncSteps.ExchangeSyncAsyncRemoteStep`2.AfterCall()    
at Microsoft.Crm.Asynchronous.EmailConnector.ExchangeSyncSteps.ExchangeSyncAsyncRemoteStep`2.Execute()    
at Microsoft.Crm.Asynchronous.EmailConnector.ExchangeSyncWorker.SynchronizeACTs()

>Exception : Unhandled Exception: Microsoft.Exchange.WebServices.Data.ServiceResponseException: Synchronization state data is corrupt or otherwise invalid.

at Microsoft.Exchange.WebServices.Data.ServiceResponse.InternalThrowIfNecessary()

at Microsoft.Exchange.WebServices.Data.MultiResponseServiceRequest`1.EndExecute(IAsyncResult asyncResult)

at Microsoft.Exchange.WebServices.Data.ExchangeService.EndSyncFolderHierarchy(IAsyncResult asyncResult)

at Microsoft.Crm.Asynchronous.EmailConnector.MonitoredExchangeService.EndSyncFolderHierarchy(IAsyncResult asyncResult)

at Microsoft.Crm.Asynchronous.EmailConnector.ExchangeSyncSteps.ExchangeSyncAsyncRemoteStep`2.AfterCall()

at Microsoft.Crm.Asynchronous.EmailConnector.ExchangeSyncSteps.ExchangeSyncAsyncRemoteStep`2.Execute()

at Microsoft.Crm.Asynchronous.EmailConnector.ExchangeSyncWorker.SynchronizeACTs()

Based on the first error message, I could elicit, that it is connected to an activity. And that it’s connected to the ACT-Settings in my Sync-Profile. Therefore I checked the settings which looked like the following:

A specific user for synchronization. This user has impersonation-rights on the mailboxes of the crm users.

Email Server Profile (Impersonation) – Microsoft Dynamics 365

Based on the Microsoft documentation https://docs.microsoft.com/en-us/dynamics365/customer-engagement/admin/best-practices-server-side-synchronization there is a hint, that ACT is not supported with Mailbox Impersonation.

Therefore I changed my profile to enter my own credentials for the mailbox and the error disappeared and the sync worked again for ACT.