When a rule checks for event availability using RulesToolkit.getEventAvailability, it needs to have Recording Setting events to be able to convert event type ids into human readable event type names. If the Recording Setting event type contains no events or is completely missing, then the resulting text will either be empty or null.

The expected behavior should be to print the event type id if the name can't be resolved.

For examples, see the result of the GC Pause Peak Duration rule when run on the attached recordings.

general_recording.jfr:

This rule requires that the following event types are enabled: null.

jmc-g1-events.jfr:

This rule requires that the following event types are enabled: .