I was told the fix will be rolled out within a few weeks globally. Stay tuned.

The Error is Could Not Synchronize record: meeting name: AccountName We are on office365 and i have a case opened already with MSFT on the issue, but wanted to see if anyone had already seen this issue.

Outlook 10.13.1 Pro Steps Are

The repro steps are: 1 have someone send you a meeting request.

Accept the meeting request.

The error should log within a minute under Sync Errors Heres the error and help would be greatly appreciated:).

The operation failed., An item with the same key has already been added.

Outlook 10.13.1 Mac OS High

Environment: Mac, Outlook 2016 ( 15.39 171010 ), Mac OS High Sierra 10.13.1, Office 365.

Connectivity: Wi-Fi on client side with inline proxy, Status of connection on most days would be described as stressed ( Line utilization is very high in our org.

Location South Africa I tried clearing the cache of the calendar, same issue, from what I can see its a database error.

Im also seeing errors downloading attachments which usually happens as a result of poor connectivity on our end.

Id like to see what results from the call you have with MSFT.

Just wanted to check if youre seeing anything of that sort on your side, this coincidence shouldnt be overlooked.

Fixes or workarounds for recent issues in Outlook for Mac We had these issues previously when latency to our 365 mail servers was very high over 15000 ms, the latency right now isnt fantastic, but nowhere near as tragic as previously experienced.

Our tenant to my knowledge is in Ireland, no available tenants on African soil yet which would account for the latency.

He has a Mac, Outlook 2016, Mac OS High Sierra 10.13.1, Office 365.

The user is in California.

The error section says: Could not synchronize record: Call to Exchange server userdomain.com Details section says: An internal server error occurred.

He says every time he gets an invite or creates a meeting and after the event is finished or passes the error arrives.

Do you have any information to fix the issue Best regards from Berlin Patrick.

On my MacBook Air running Sierra 10.12.6, Outlook 15.39 (171010) using Office 365, I received the same error code: -19874 I accepted a meeting this morning and noticed the exclamation point in the lower right corner of the Outlook windows indicating there was a problem.

Attached is the screen shot of the error messages I received.

I did 3 different tests on the same day (today) and each one received the synch error.

Also tried removing the profile in Outlook and emptying the cache for the calendar.

According to MSFT, there isnt a fix for this issue at this time, but They are looking into it.

Here is what I am running and also receiving the same error message, so it sounds like it isnt an outlook specific version issue.

Outlook for Mac 2016 Diagnostic Log Outlook for Mac 2016 Build: 16.8.17110100 Activation Type: Subscription Microsoft AutoUpdate Build: 3.11.17101000 Mac OS Version: Version 10.13 (Build 17A405) Audience: InsidersDevMain AudienceGroup: Insiders Channel: DevMain Computer name: Not Logged Current Time Zone: AmericaLosAngeles Default Profile Name: Not Logged Profile Path: Not Logged Proxy Settings: Not Logged.

I was told the fix will be rolled out within a few weeks globally.

Outlook For Mac 10.13.1