WARNING: [4652-33-174-00000000] is observed in the log file after the migration.
May be followed by:
Skipping non-mail message. Notes ID: 0x80000004
Invalid or deleted note
May be caused by inconsistent state of data in Domino, residual data which was not properly removed or problems with the formatting of the messages. Please click here to get further details regarding how to repair Notes DB corruption.
Can also indicate that the messages have already been migrated in a previous migration or they exist in multiple folders on the source side.