New Post: Multiple Select ParentColumn?

That warning message is something else, so not part of this issue.

If you've renamed the Title column, then its StaticName is still Title. So the line:

relationshipListChildColumn: "Location_x0020_Name",

would be:

relationshipListChildColumn: "Title",

However, you should get a debug message if there is no Location_x0020_Name column.

M.