My changesets are not being picked up but I see them in TFS. What could be wrong?
If you have run the tool before on the same source server, it “remembers” changesets that were already migrated from the last attempt and keeps track of the last changeset that was migrated (it stores a “high watermark”). To restart a migration, see the question and answer below. You can also safely delete the TfsMigration database if you truly want to restart a migration, the tool automatically recreates the database the first time that the tool is run.