That is a basic error actually and nothing I programmed in... all I've done is trapped the error. Error 6 is an 'overflow' which means, for instance, I might have been expecting to read data into a variable assigned as a byte but the data was too large.
And have you checked the AutoPilot type setting in the performance file you're using and are you sure you are using that performance file? Remember user performance files appear at the end of the drop down listing, prefixed with the word 'User:'