I think the reason for the loading loop and SQL Report Builder crashing when I run this report is something to do with the date selection format I have set up or it needs changing. Within SMSS the datatype of the scheme.pallet.PAL_date is datetime, I have formatted the text box on the report as Date DD/MM/YY (and set the parameter as date selection) but it doesn't seem to make any difference. As said the query works fine in SSMS but just not as a report in SSRS?