[ovirt-users] Gluster event logging

I'm running oVirt 4.3.2, and just upgraded gluster to 5.5. I see that the gluster event daemon now works, however the events are not being processed by the ovirt engine. On the engine side I'm seeing: "engine.log:2019-03-25 17:14:04,707-04 ERROR [org.ovirt.engine.core.services.GlusterEventsWebHookServlet] (default task-198) [] Error processing event data" in the engine log. On the gluster servers in event.log, I'm seeing: "[2019-03-25 17:14:04,704] WARNING [utils - 272:publish_to_webhook] - Event push failed to URL: http://ovirt-engine:80/ovirt-engine/services/glusterevents, Event: {"event": "CLIENT_CONNECT", "message": {"brick_path": "/gluster_bricks/ISO/ISO", "client_identifier": "10.10.15.12:49120", "client_uid": "CTX_ID:d988b64d-2996-44c4-88ed-ee768c9e0c21-GRAPH_ID:0-PID:43711-HOST:ovirt2-PC_NAME:ISO-client-2-RECON_NO:-0", "server_identifier": "10.10.15.12:49155", "subdir_mount": "(null)"}, "nodeid": "9a6ea54e-c692-45bd-889b-ed20c6fb1145", "ts": 1553548444}, Status Code: 500" How can I determine why these events are not getting processed? Thanks,