Step 10: Process Modeling 101, part 2 (Create Related Action)

New to Appian,

Hello, I'm doing step 10: Process Modeling 101, part 2. When creating a Related Action, step 7 of the exercise, when i click REQUEST MAINTENANCE to test the action, this error message appears

(An error occurred while applying the context for the W0112AX Vehicle related action [identifier=41,530]. Details: No process parameter found corresponding to override [name=pv!vehicleId]. Non-parameter process variables cannot be overridden.)