I suspect this is data related, with POI Loader choking on something in that cache's data. One way to narrow it down would be to delete all of the logs from that cache and try again. If it still fails, we know the issue is in the cache descriptions or hint. if it succeeds, we know the problem is in the logs. Either way, we can delve more deeply into what might be causing the issue once it's been narrowed down (e.g. if it is the logs, try deleting those where the log owner has an apostrophe in their name to see if that solves the problem).
