Duplicate ID on Sequence [Microsoft.Sharepoint.Portal.Upgrade.FarmSequence]

Over the last couple of months I have been involved in upgrading our current MOSS 2003 Intranet to MOSS 2007. All I can say that it has been eventful to say the least with numerous errors popping up left right and center. I am sure I will be posting more in future regarding my Sharepoint upgrade experience.  Anyway, back to this post. When I attempted to add a content database to my MOSS 2007 Intranet I got the following error:

"Duplicate ID on sequence [Microsoft.Sharepoint.Portal.Upgrade.FarmSequence]"

Interesting...

The cause of this error resides in the Upgrade Definition files located in  "C:\Program Files\Common Files\Microsoft Shared\web server extensions\12\CONFIG\UPGRADE" directory. The Upgrade Definition files tell Sharepoint where to dump the old content in the new database during the upgrade process. Even though the error message is not helpful in any shape or form, the solving this error is not too bad.

Locate the following two XML files within the UPGRADE directory: SPSUpgradePremium.xml and SPSUpgrade.xml. Then all you need to do is delete the following line that looks something like this in both files:

<Assembly Name="Microsoft.SharePoint.Portal.Upgrade,Version=12.0.0.0,Culture=neutral,PublicKeyToken=71e9bce111e9429c,Custom=null">
    <Order>5</Order>
</Assembly>

I just hope the other Sharepoint upgrade errors that appear will be more straight forward...