I think if this is your code you may have a clue with isolating where the problem may be rather than providing a entire code dump. But I did find -->
insert into #tempFPRA exec (@start_Date+','+@end_date)
...
SET @WeekStartDate = (SELECT sdate FROM #tempFPRA)
If #tempFPRA has more than one row at this point, this will cause the exception you speak of. I don't know if this helps.
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