# behaviour-prop-unknown

> Talos 0.7 · Since 0.6

a `class X extends Behaviour` was given a script prop with no field of that name, so it would set nothing (thrown in `init`, which disables the behaviour); the message lists the fields

| | |
|---|---|
| Severity | `error` |

## Meaning

a `class X extends Behaviour` was given a script prop with no field of that name, so it would set nothing (thrown in `init`, which disables the behaviour); the message lists the fields

## Fix

name a field the class declares with a value (`speed = 3`), or add the field; `playtest` is the engine's and never refused