'answerPromptsEx' API. (Error: ERR_WIS_30270) Error in Dashboard

Hi. I'm working on a Dashboard in Business Objects 4.1. It was previously in XIR3 and has been migrated across. When refreshing I am getting the following error:

An internal error occurred while calling 'answerPromptsEx' API. (Error: ERR_WIS_30270)

The Dashboard is populated via two QAAWS's which both take date parameters. I have done some googling of the error and I can see that this error is associated with QAAWS that use date parameters but I cannot find a definitive answer as to what the fix is for Business Objects 4.1.

Please can someone advise?

Thanks in advance.