@RISK/Risk Optimizer Error: "The cell ... is part of an array formula."

@RISK can’t replace formulas inside array formulas, so RiskOutput and most @RISK functions must be moved out; use SUMPRODUCT or reference the array from a normal formula.

Jan 22, 2026
Knowledge

Title

Answer

Applies to:
@RISK 5.x–7.x
RISKOptimizer 5.x

Errors:

"The cell is part of an array formula.... @RISK outputs cannot be part of array formulas."
"...@RISK distributions cannot be part of array formulas."

Details:

To speed calculations, @RISK temporarily replaces formulas containing RiskOutput() and other @RISK functions during simulation, then restores them afterward.

This replacement cannot be done with array formulas, which is why you see the message.

Exceptions:

RiskData() works in array formulas.
Time Series Fit and Batch Fit create array formulas by design.

Workarounds:

Avoid array formulas if possible. Many can be replaced with SUMPRODUCT(), which is faster and compatible.
Separate the @RISK function from the array formula.
- Put only the array logic in one cell (entered with Ctrl-Shift-Enter).
- In another cell, use a normal formula like =RiskOutput()+that_cell.

If the array formula contains other @RISK distributions or stats (besides RiskData), you’ll also need to move those functions out of the array formula and reference them separately.

Placing Iteration Data in Worksheet with RiskData( )

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the-cell-is-part-of-an-array-formula