Troubleshooting

Start with the earliest failed layer. Do not debug combat behavior if the API or mod owner failed to register.

1. Confirm the environment

Record the FTK2, ModAPI, BepInEx, Harmony and Unity versions from the startup log. Compare them to Requirements.

2. Confirm core startup

Look for successful API initialization and a registered consumer. If the ExampleMod validation harness is installed, check the CORE-* and MOD-* results before content-specific tests.

3. Confirm ownership and IDs

For registration failures, verify the content namespace matches the registered owner. An ownership error is intentional protection, not a reason to bypass validation.

4. For custom items

Check definition registration before activation, then localization, visual aliases and runtime/save state in that order. If a save load is blocked, read the missing-definition IDs and restore the required content instead of forcing commit.

5. For custom abilities

Separate definition/activation success from downstream consumer success. In 0.5.4 the ability can be active while a later tooltip/combat consumer boundary is still incomplete.

Diagnostics to attach

Use Bug Reports for the minimum report bundle.