Below is a list of common error messages you might encounter when using the data migration service and some possible solutions.
For information on error codes you might find when using the data migration service, go to Data migration service error codes.
| Error message | Description |
|---|---|
| Internal Server Error | Default error code. Displays when any unspecified system error occurs. |
| Error communicating with the Exchange Server | Unable to communicate with the Microsoft Exchange Server. |
| Error communicating with the source mail server | Unable to communicate with the source mail server. If you're migrating from a Google Workspace account or Gmail, review the Gmail prerequisites. For details, go to Personal Gmail account. |
| Error in mailbox configuration or content | There are errors in the mailbox configuration. |
| Exchange Authentication Failure |
The source credentials you are using for your Exchange server are unauthorized or entered incorrectly. Also, check that your role account has been granted impersonation rights. For details, go to Role account. |
| Google Workspace Authentication Failure | There's a problem retrieving the access token. This only happens when the API key is removed. |
| Error in the message content | There are errors in the content of the migrated mail messages. |
| Unable to open mailbox. Verify that mailbox exists and is accessible to the administrative account used for migration. | The credentials for a particular mailbox on the source server aren't working. For IMAP migrations, verify that the username and password you entered are correct. For Exchange migrations, check the impersonation settings. For details, go to Migrating from an EWS environment. |
| Source user mailbox is disabled | The user's mailbox on the source server is turned off. |
| Invalid Google Workspace User ID | The mailbox or email service for this user isn't turned on. Correct this and try again. |
| Error when trying to synchronize a deleted folder from source mailbox | An error occurred while syncing a deleted folder. |
| Impersonation for Exchange not set | You must set up impersonation rights in Exchange for this mailbox. Check the impersonation settings. For details, go to Migrating from an EWS environment. |
| Exchange Web Services (EWS) virtual directory is not set | You must define a virtual directory in Exchange Web Services. Consult your Microsoft documentation for further information on creating a virtual directory. |
| The given/detected Exchange Web Services url is invalid (30x redirect occurred) | The URL provided or detected for EWS is invalid. Verify the EWS URL and check that it's accessible using the Microsoft Remote Connectivity Analyzer tool. After you confirm that the EWS URL is working, try migrating again. |
| An error occurred | An undefined error has occurred. |
| Authentication error. The username or password you entered is incorrect. Please verify. |
The username or password you entered is incorrect. Verify this information and try again. You can also try to sign into another system that shares the same credentials as the data migration service (for example, an IMAP email client) to verify your information. For IMAP migrations, make sure IMAP is available at the source account. For details, go to Check Gmail through other email platforms. |
| SSL certificate is not installed properly on Source server | The TLS/SSL certificate is either not installed or installed incorrectly on your source server. For details, go to Set up your TLS certificate. |
| An ISA (Internet Security and Acceleration) error occurred on Exchange server. Please make sure that Autodiscover rule is set correctly. | Verify the Autodiscover settings on your Exchange server using the Microsoft Remote Connectivity Analyzer tool. |
| Validation of settings failed! | Check the source server to make sure your credentials are correct. For details, go to Prepare your source account. |
| Error starting migration. The authorization code for one or more users is invalid. | Your authorization code might have expired. Authorization codes are only valid for 10 minutes from the time of generation. Generate new authorization codes and restart the migration. |
| Not able to access Contacts for the user | Permission has been denied for the user to access Google Contacts. |
| Contacts storage quota exceeded | Verify the user has enough space to store external contacts. For details, go to Add shared external contacts to the Directory. |
| Google Workspace user account is deleted | The user might have been deleted from Google Workspace while the migration was running. |
| Invalid user in attendee mappings. Make sure that all the users provided are actually provisioned in Google Workspace. | The attendee mappings provided during the setup phase are invalid. Fix the issue and set up the migration again with the correct mappings. |
| Error fetching emails from the folder | The specific folder could not be opened or processed. This is most likely due to a transient network issue, such as a dropped connection or a connection timeout. Check your network and try again. |
| Unknown error: Error (Retrying)Unknown error | The target user account doesn't have a valid license or the Gmail service is turned off for the user. For details, follow the steps in Set up your new Google Workspace account. |
Related topics
- Troubleshoot the data migration service
- Data migration service error codes
- Data migration service FAQ
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