Using NON EMPTY is not permitted. See long text

What causes this issue?

NON EMPTY cannot be used at this position in the statement.

System Response

Execution of the MDX statement ends with an error.

How to fix this error?

Check the use of the MDX statement. If the statement is a nested MDX
statement, NON EMPTY can only be used in the outermost MDX statement.

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.