# S03005 {#s03005}

## Error Code {#error_code .section}

S03005

## Error Message {#error_message .section}

`The reactive state engine doesn't support the aggregate function <%funcName> in metrics <%groupMsg>. RefId:S03005`

\("%funcName" refers to the name of the specific aggregate function.\)

## Probable Causes {#probable_causes .section}

This error occurs when the parameter *metrics* in `createReactiveStateEngine` or parameters *metrics1* and *metrics2* in `createDualOwnershipReactiveStateEngine` use built-in aggregate functions.

## Solutions {#solutions .section}

Specify optimized built-in functions to *metrics*\(see [createReactiveStateEngine](../../Functions/c/createReactiveStateEngine.md#) for supported functions\), or use an aggregate function within a user-defined stateless function \(without `@state` declared\).

**Parent topic:**[Error Code Reference](../../Troubleshooting/ErrorCode.md)

