Data migration service error messages

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 G Suite account, Gmail, or Google Account, review the Gmail prerequisites. Learn more
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 the username and password you entered are correct. For Exchange migrations, check the impersonation settings. Learn more
Source user mailbox is disabled The user's mailbox on the legacy server is turned off.
Invalid G Suite User ID The mailbox or email service for this user is not 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. Learn more
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 starting the migration 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 to verify your information. For example, an IMAP email client.

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 legacy server. Learn more
An ISA (Internet Security and Acceleration) error occurred on Exchange server. Please make sure that Autodiscover rule is set correctly. Data migration Check the Autodiscover settings on your Exchange server and verify them using the Microsoft Remote Connectivity Analyzer tool.
Validation of settings failed! Check the legacy environment server settings to make sure your credentials are correct. Learn more
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. Learn more
G Suite user account is deleted The user might 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.
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.

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