StalledDueToTarget_Processor error during Exchange migration in Microsoft 365

Original KB number:   3162761

Symptoms

When you perform a Microsoft Exchange Server migration, you receive a StalledDueToTarget_Processor error message. This problem occurs in Microsoft 365.

When you view the data in the move report, the report contains an error message that resembles the following:

{DataExportTransientException: MapiFxProxyTransientException: The data export was cancelled
due to a timeout. The destination didn't respond in time. --> The data export was cancelled
due to a timeout. The destination didn't respond in time., DataExportTransientException:
MapiFxProxyTransientException: The data export was cancelled due to a timeout. The
destination didn't respond in time. --> The data export was cancelled due to a timeout. The
destination didn't respond in time., DataExportTransientException:
MapiFxProxyTransientException: The data export was cancelled due to a timeout.

To view the move report, run the following command:

Get-MoveRequest -Identity <User> | Get-MoveRequestStatistics -IncludeReport | FL

Cause

This problem occurs when the MRS Proxy for the mailbox move request is a configuration on the on-premises Exchange Server 2013 Client Access server (CAS).

Resolution

To fix this problem, you must change the MSExchangeMailboxReplication.exe.config file. To make the required change, follow these steps:

1. Locate the MSExchangeMailboxReplication.exe.config file in the following path:

   <Exchange Installation Path>\Program Files\Microsoft\Exchange Server\V15\Bin\MSExchangeMailboxReplication.exe.config

2. Change the DataImportTimeout setting from the default value to 20.

3. Save the changes to the file.

4. Restart the MSExchangeMailboxReplication service.

5. On all CA servers, change the DataImportTimeout setting to 20.

6. Allow up to four hours for the migration batches to resume as usual.