The report works in splunk, the scheduled jobs ran, a dashboard presents the reports, but the embeded report in Chrome, ie, shows "Report not available". I am on 6.3.2 Splunk
I talked with our admins and they restarted splunkweb process that morning to clear up another issue, but they didn't restart splunk, so they think they got out of sync. The restarted both, and afterwards, the embedded reports worked again. So I recommend, restarting your splunkweb and splunk.