There is no HistoryEventType for User Operation Log Entries.
- whether these entries are produced cannot be configured in a custom history level
- the value of HistoryEvent.getEventType() is null which has to be dealt with in custom history handlers
A (non-public API) workaround exists for both cases by checking the type of the history event object first.
Related forum post: https://groups.google.com/forum/#!topic/camunda-bpm-users/rYQjy70Wj48