Data migration service error messages

Below is a list of common error messages that you may come across when using the data migration service and some possible solutions. 

For information on error codes you may see when using the data migration service, see 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 Exchange Server.
Error communicating with the source mail server Unable to communicate with the source mail server. If you're migrating from a G Suite account, Gmail, or Google Account, please review the Gmail prerequisites.
Error in mailbox configuration or content There are errors in the mailbox configuration.
Exchange Authentication Failure The legacy credentials you are using for your Exchange server are unauthorized or entered incorrectly.
G Suite 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 your mail.
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 legacy server are not working. For IMAP migrations, verify that the username and password you entered are correct. For Exchange migrations, ensure that you've enabled impersonation.
Source user mailbox is disabled The user's mailbox on the legacy server is disabled.
Invalid G Suite User ID The mailbox or email service for this user is not enabled. 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 permission in Exchange for this mailbox. Consult the Microsoft Knowledge Base for more information.
Exchange Web Services (EWS) virtual directory is not set You must define a virtual directory in Exchange Web Services. Consult the Microsoft Knowledge Base for more information.
The given/detected Exchange Web Services url is invalid (30x redirect occurred) The URL provided or detected for Exchange Web Services is invalid. Verify this information and check that it's accessible using the Microsoft Remote Connectivity Analyzer. After you confirm that the EWS URL is working, try starting the migration again.
An error occurred An undefined error has occurred.
The username or password you entered is incorrect

The username or password you entered is incorrect. Verify this information and try again.

For IMAP migrations, ensure IMAP is available at the source account. For details, see Use IMAP to check Gmail on other email clients.

SSL certificate is not installed properly on Source server The TLS/SSL certificate is either not installed or installed incorrectly on your legacy server. See Set up your TLS (SSL) certificates.
An ISA (Internet Security and Acceleration) error occurred on Exchange server. Please make sure that Autodiscover rule is set correctly.Data migration  Check Autodiscover settings on your Exchange server and verify them using the Microsoft Remote Connectivity Analyzer.
Validation of settings failed! Check the server settings to make sure your credentials are correct.
Error starting migration. The authorization code for one or more users is invalid. Your authorization code may have expired. Authorization codes are only valid for 10 minutes from the time of generation. Generate any 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 that user has enough space to store contacts. See Directory storage limits for details.
G Suite user account is deleted The user may have been deleted from G Suite while the migration was running.
Invalid user in attendee mappings. Please make sure that all the users provided are actually provisioned in G Suite The attendee mappings provided during the setup phase are invalid. Fix the issue and set up the migration again with the correct mappings.
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