SSAS converts empty fields into string text 'NULL'. I found out because my report shows NULL as string value. Running the MDX query in SSMS, it shows NULL as well, while other fields remain empty.
I tried all the ppossibilitieswith the NullProcessing option, but with no results.
In report server I covered the result by using the following expresion,
but there must be a better way, am I missing something here?