In [`ParsingCallback::OWL`:43](https://github.com/ontohub/ontohub/blob/f58896972961d2c091a187935793dfc1ae2d643e/lib/parsing_callback/owl.rb#L43) you rescue from an `ActiveRecord::RecordNotFound` error, in order to prevent that a not-found entity/object would result in an abort of the ontology-parsing procedure.

Here the same would apply. If you do not rescue from `ActiveRecord::RecordNotFound` one ungenerateable tree for one ontology would result in other ontologies ending up without a tree; as it would brake out of the `ontologies.each`-loop and the task.