If I have a workflow state defined as:
<step id="7" name="Closed">
<meta name="jira.issue.editable">false</meta>
<meta name="jira.status.id">6</meta>
</step>
then JIRA issues in this state do not have an OS_CURRENTSTEP record (as there are no outgoing transitions), and the Integrity Checker marks such issues as invalid.