(Exception has been thrown by the target) error when moving mailboxes to or from Microsoft 365 in a hybrid deployment

  • Article
  • Applies to:
    Office Products, Exchange Online, Exchange Server 2010 Standard, Exchange Server 2010 Enterprise

Note

The Hybrid Configuration wizard that's included in the Exchange Management Console in Microsoft Exchange Server 2010 is no longer supported. Therefore, you should no longer use the old Hybrid Configuration wizard. Instead, use the Microsoft 365 Hybrid Configuration wizard that's available at https://aka.ms/HybridWizard. For more information, see Microsoft 365 Hybrid Configuration wizard for Exchange 2010.

Problem

You have a hybrid deployment of Microsoft Exchange Online in Microsoft 365 and your on-premises Microsoft Exchange Server environment. When you try to move mailboxes to or from Microsoft 365, you receive the following error message:

Exception has been thrown by the target of an invocation.

You were previously able to successfully move mailboxes to or from Microsoft 365 and your on-premises Exchange Server environment. You experience this symptom only after you upgrade the on-premises environment from Exchange Server 2010 Service Pack 1 (SP1) to Exchange Server 2010 Service Pack 2 (SP2) or later.

Cause

This issue occurs if the Web.config file was overwritten during the upgrade from Exchange Server 2010 Service SP1 to Exchange Server 2010 SP2 or later. Remote mailbox moves require the Mailbox Replication Proxy (MRSProxy) service endpoint to be enabled on the Client Access server. In Exchange Server 2010 SP1 and Exchange Server 2010, the MRSProxy setting is configured in the Web.config file.

In Exchange Server 2010 SP2 or later, the MRSProxy settings are stored in Active Directory and are configured by using the Set-WebServicesVirtualDirectoryWindows PowerShell cmdlet.

Note

There are several possible causes of this error message. This article discusses one scenario that may cause this error message.

Solution

Use the Set-WebServicesVirtualDirectory cmdlet to re-enable MRSProxy on every Client Access server in the on-premises environment through which you want to let remote move requests pass. To do this, follow these steps:

  1. Open the Exchange Management Shell.

  2. Make sure that the MRSProxyEnabled parameter on the server is set to false.

    To do this, run the following cmdlet:

    Get-WebServicesVirtualDirectory-Identity "Server\EWS(default Web site)"

  3. Enable the MRSProxy service. To do this, run the following cmdlet:

    Set-WebServicesVirtualDirectory-Identity "Server\EWS(default Web site)" –MRSProxyEnabled $true

More information

After you enable MRSProxy on the servers, you may have to correctly publish the endpoint through your firewall. For more information about how to do this, see Configure Forefront TMG for a hybrid environment.

For more information about how to troubleshoot the error message that's mentioned in the Symptoms section, see Exception has been thrown by the target error in a hybrid deployment.

If you experience issues when you move mailboxes to Exchange Online in Microsoft 365, you can run the Troubleshoot Microsoft 365 Mailbox Migration tool. This diagnostic is an automated troubleshooting tool. If you're experiencing a known issue, you receive a message that states what went wrong. The message includes a link to an article that contains the solution. Currently, the tool is supported only in Internet Explorer.

Still need help? Go to Microsoft Community or the Exchange TechNet Forums.