That error message would mean that you haven't applied all the updates from your SQL folder, but I thought that would be obvious as it says it right there in the error message.
For me, this would be C:\\wherever-you-downloaded-your-mangos-core-stuff-to\\sql\\updates
then, you find all the updates, starting from the update AFTER the currently listed on your mangosd.dbversion (assuming you followed this guide when naming your databases) table on the database (in your case hagro, start updating from **8749_01_mangos_mail_loot_template**. You'll find this in the 0.15 folder) that have the word mangos in them somewhere, leading all the way up to the latest available one in the folder.
Hope this helps.
edit: Judging from the rest of the topic thus far, this should help a lot of you.