AddDelegate: Failed to add one or more delegates during Outlook synchronization

[Jrouzies]

Hello,

We have an issue setting Delegate users to one specific user, with the generic error "Failed to add one or more delegates", only when this user is synchronization his account on Outlook.

I was not able to reproduce the case, still it happened the following way:

1. User has one or more delegates configured (can get the list with GetDelegate)
2. User starts an "old" computer with a Outlook where the account synchronization was not finished (started again as he starts the computer)
3. Synchronization cannot finish due to no free space on the local OST disk

I tried to reproduce a similar situation by adding an account with OST on a disk with too low free space for it to synchronize fully, but it didn't stop me to edit delegates for the test account even if the synchronization was not finished.

My issue is that very often when this user (you guess, the big boss of the company) starts a computer where Outlook is synchronizing, we cannot Add delegates until the synchronization is over with the generic error in EWS logs (C:\Program Files\Microsoft\Exchange Server\V15\Logging\Ews):

ExceptionHandler_Execute_Multiple=Microsoft.Exchange.Services.Core.Types.DelegateSaveFailedException: Failed to add one or more delegates. at Microsoft.Exchange.Services.Core.AddDelegate.PostExecuteCommand() at Microsoft.Exchange.Services.Core.MultiStepServiceCommand2.<>c__DisplayClass4.<InternalPostExecute>b__3() at Microsoft.Exchange.Services.Core.ExceptionHandler1.Execute(CreateServiceResults createServiceResults GenerateMessageXmlForServiceError generateErrorXml);

Is there a way to implement better logging or did someone already saw this issue and knows where it could come from?

Thanks

[hirnerstefan]

Hello, did you find the solution here? I have the same problem with a few users. many thanks in advance Stefan