An addon did not load
- Confirm the JAR is directly inside plugins/Foundry/packs. The loader does not recursively search subfolders.
- Confirm foundry.yml is at the JAR root, not inside a nested directory.
- Check that id matches the addon's id and uses only lowercase letters, digits, underscores, and hyphens.
- Check that main names a class in the JAR that implements FoundryAddon and has a no-argument constructor.
- Check server startup logs. Foundry logs a warning for a missing descriptor and a severe error for descriptor, class-loading, or enable failures.
An ability did not activate
- Register the ability before assigning or triggering its ID.
- Assign it with playerAbilities.assign for the exact Action being used.
- Check whether the input was made while sneaking or with the offhand; those use distinct actions.
- Physical interactions are ignored. The listener handles left and right click in air or on a block.
- A registered ability on cooldown does not activate. The interaction is still cancelled once a registered player binding is found.
Configuration and reload
The current core does not load a user-editable Foundry configuration file and does not expose a reload command. The foundry.yml file belongs inside each addon JAR and is its descriptor, not a server configuration file.