Click the Process Transaction button instead of bulk processing the transaction if modifications have been made to the transaction before processing it.  

If the error persists, it may be necessary to add the City Name to the Cities Table in the Raiser's Edge.

1.  Select Config from the menu on the right
2.  Select Tables, and choose the table that has the list of available cities
3.  Click the New Table Entry button at the top, and type in the name of the city that is causing the error
4.  Click OK
5.  Select the NetCommunity Plugin, and Click Process Transaction