"Calculation depends on calculated slots" Error appears in all rows for a column

I have an FSG report containing following columns:

Parameter Month / Sales % / Parameter Month Last Year / Sales % / Monthly Difference / Sales %

Parameter Month = PTD-Actual, Offset = 0

Sales % = % of 'Parameter Month'

Parameter Month Last Year = PTD-Actual, Offset = -13

Sales % = % of 'Parameter Month Last Year'

Monthly Difference = 'Parameter Month' - 'Parameter Month Last Year'

Sales % = 'Sales %' - 'Sales %'

Issue:

The output for 3rd 'Sales %' shows "Calculation depends on calculated slots" in all rows for that column instead of showing the difference between 1st 'Sales %' and 2nd 'Sales %'.