There was an unexpected error (type=Internal Server Error, status=500). Could not write JSON: Java 8 date/time type `java.time.LocalDateTime` not supported by default: add Module "com.fasterxml.jackson.datatype:jackson-datatype-jsr310" to enable handling (through reference chain: java.util.ArrayList[0]->Bulletin.Board.domain.posts.Post["createdDate"]); nested exception is com.fasterxml.jackson.d..