Null Object loaded from local variable error in Webi 4.1

Hi,

I am changing the connection for a BEX query from Bo 4.0 to BO 4.1 SP3 patch2 in Webi 4.1. I am getting the error i.e.

"while trying to invoke the method java.util.date.gettime() of a null object loaded from a local variable 'date' "

where as the under lying BEx query is perfectly executing in BEx Analyzer.