# Diagnose gameplay actions [Back to Use gameplay actions](https://rustic-game-engine.pages.dev/markdown/guides/gameplay-actions.md). If nothing moves, check attachment/enabled state, press Play, anchor the Part, and check the Console. For external languages, check toolchain discovery; Java needs both `java` **and** `javac`, not just a JRE. An unsupported property, wrong value type, or unavailable perspective camera is an error, not a successful action. Asynchronous target errors appear in operation state and the Console. Schedule through `Start` or an event/callback; API state is not initialized at script top level. Callback exceptions disable the owning behavior and clean its actions.