Kafka SerializationException: Schema Not Found (40403) Fix
Kafka consumer dies with SerializationException: Error retrieving Avro schema for id N, Schema not found; error code: 40403. Why the ID lookup fails and how to fix it.
schema-registry
2 PostsSchema Being Registered Is Incompatible: Kafka 409 Fix
Fix "Schema being registered is incompatible with an earlier schema; error code: 409" — why Schema Registry rejects your schema and how to evolve safely.