Hi Ben,
When upgrading from Mendix 8 to 9, the option to use legacy parameters is dropped. This means that the Java code probably needs to be updated, as ImageParameter1 is not available anymore.
You could do this yourself, or check if you can update the AuditTrail module from the Marketplace. Verify during deployment if your entities are untouched, otherwise the whole goals of AuditTrail might be gone.
Good luck!
Johan