#MULTIVALUE When it Occurs and How Do I resolve it

I have a query and report built from two different data providers. One of the data providers is a reference universe that I have a query called Material Item which provides descriptive informaiton about an item of a shipment that I want to include in my shipments report. I've merged the dimensions of the two queries on "Material Item Identifier" I then added the joined dimension Material Item Identifier, and also a detail object (Material Item Name) I created since it wouldn't let me drag and drop this dimension on the report saying "incompatible object".

The problem I am having now is the detail object column in the report called "Material Item Name" some of the fields display the item name as it should, and then other fields give me the #MULTIVALUE. How do I need to change the report to get rid of the #multivalue and so the item name displays in the column right after Material item identifier in my shipments report?