As always, direct access to the database schema is not encouraged, since the schema is NOT an API and is subject to change at developments whim, and SE will therefore not officially support this, however given those caveats, running the following query against the PAM run time database
SELECT d.ROID, d.Instance AS 'Process Instance', d.RunState AS 'Run State' from c2oruntimeobjects d where
d.callerType='AGENDA' and
d.DiscriminatorType='WorkFlow' and
d.RunState IN ('Failed’, ‘Blocked’)
will list all processes that were directly started from a Schedule (formerly Agenda), and exited through an AbnormalStop operator, or are blocked.