Description
When appending GTFS data to existing public transit data model feature classes and tables, these existing tables and feature classes must all be present and have the correct schema. This error indicates that one or more of the required tables or feature classes does not exist in the target feature dataset or its parent geodatabase.
Solution
You cannot append GTFS data to the existing public transit data model tables and feature classes if any of those tables and feature classes do not exist. You cannot append with this target feature dataset.