Symptoms
When interacting with a discussion board migrated with ShareGate Migrate, one of the following behaviours can occur:
The Last Updated property of the discussion is not updated when we reply to a comment.
The subject of quotes in a reply is set to "(no title)".
Replies on a message that was originally a reply are not displayed by SharePoint. The reply count is updated, but the text is not shown.
Details
When migrating a discussion board, ShareGate Migrate is unable to keep a reference between the message and its replies. All messages are kept in the right discussion, but the hierarchy between them is lost and all messages are displayed as the original message of the discussion. To continue the discussion, the users must reply to the original message or use the "Add a reply" section at the end of the page. The reason for this is that a message uses 2 internal self lookup values which keep the reference to the discussion and those values cannot be set manually.
Example :
Source
Destination
