Error while refreshing and Scheduling WebI Report

Hi Experts,

I am getting a strange error while refreshing or Scheduling a WebI Report . The error says:

" while trying to invoke the method com.sap.ip.bi.bics.dataaccess.consumer.queryview.resultset.IRsAxisTupleElement.getCharacteristicMember() of a null object loaded from local variable 'element' "

If I cancel the error and refresh again the report works fine, scheduling of report always fail.

This is happening in our QA environment where as the same report works fine in Dev.

Current BO Version : 4.1 SP05

Any inputs for the similar experience will be much appreciated.

Thanks,

Vib