If statement total error

Anonymous , Try like

Inventory_Result_Calculation_Year =
VAR AvgFISCPER = AVERAGE('src_horizon v_horizon_aggregate'[FISCPER])
VAR AvgCurrentFISCPER = AVERAGE('src_horizon v_horizon_aggregate'[CURRENT_FISCPER])
VAR MaxYear = MAX('src_horizon v_horizon_aggregate'[YEAR])
VAR MaxMonthNumber = MAX('src_horizon v_horizon_aggregate'[Month_Number])
VAR MaxWeek = MAX('src_horizon v_horizon_aggregate'[WEEK])
VAR MaxProductGroup = MAX('src_horizon v_horizon_aggregate'[PRODUCT_GROUP])
VAR Result =
IF(
AvgFISCPER < AvgCurrentFISCPER,
SUM('src_horizon v_horizon_aggregate'[ACT_INV]),
BLANK()
)
RETURN
CALCULATE(
SUM('src_horizon v_horizon_aggregate'[INVENTORY_NATIONAL]),
FILTER(
ALLSELECTED('src_horizon v_horizon_aggregate'),
'src_horizon v_horizon_aggregate'[YEAR] <= MaxYear
),
ALL('src_horizon v_horizon_aggregate'),
Result
)