An item with the same key has already been added when using the Transporter for Lotus Notes

When migrating domino mailboxes using the Lotus Notes Transporter for Exchange 2007, you may encounter the following error:

"An item with the same key has already been added."

From the Transport Powershell we see this error:
Move-DominoMailbox : An item with the same key has already been added.

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I have ran across this error a couple of times, i cant tell you exactly what seems to be causing it. It appears to be something inside of the nsf for the user so we will want to run the 3 step magic trick on it as follows:

Run the following Domino command line utilities on the Domino mail file; typically shortname.nsf.

Note: You will be prompted for and must know the user.id and password for the Domino mail file.

In the following examples, replace shortname.nsf with the Domino mail file that failed during the migration attempt.

C:\Program Files\Lotus\Notes\nfixup shortname.nsf -f
C:\Program Files\Lotus\Notes\nupdall shortname.nsf -r
C:\Program Files\Lotus\Notes\ncompact.exe shortname.nsf

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