I am trying to create a moving average of a report calculated column and can do it in the data view but as soon as I go to add it to a chart I get an error

Analytical function Date Column has been assigned a parameter field that is no longer valid.

The calculated column is using a subquery column and sum aggregation I don't know if that makes a difference

Unscheduled Removal Rate (URR) = ( Unscheduled Removals * 1000 ) / Hours Flown by Fleet in Report Month

Unscheduled Removal is a sum from the subquery .

The 3 Month Moving average on the URR is what is causing the problem any ideas ?