Check http://blog.jlcconsulting.com/PermaLink,guid,e6c85bdc-25c1-4d68-9148-8507912e7fb3.aspx

>I am trying to make a simple installation with Install Shield Express and keep coming up with the following error:
>
>ISEXP : error -6264: A record in the Property table is using string ID 'ID_STRING1' for column 'Value' but this string is blank and the column is not nullable
>
>For the life of me I can not seem to figure out what I am missing.
>