New Sermon page won't load

I finally launched the site I was working on (thanks for your help on my previous post). Something is going wrong when we try to create a new Sermon. The page loads partially after a long delay but there's no header info. I was able to create Sermons at the beginning of my development process, but I'm not sure where along the way this error popped up.

I can successfully create new Categories, Series, and Speakers, and can edit existing sermons, so it seems like it's just creating new Sermons that has trouble. I'm happy to post a URL and login details if there's a way to do that securely. I've already tried reinstalling Sermon Speaker, and the error log doesn't have any clues.

Here's the admin page that finally loads:


And here's the source code:

The error log doesn't have anything new, but I'm embarrassed that I didn't think to turn on error reporting. Setting it to Development gave me the following error:

That part of the file referred to listing bucket contents on S3, which we do use. So I've been chasing things on AWS for the last couple of hours. The problem seems to be related to bucket permissions. I've deleted and re-created users and policies with no luck, but I'm still trying to figure it out. I'll keep on this, but I may be back later with additional questions. Thanks for the help.

I got it fixed, but I still don't know why. My original bucket won't work at all. I created a new bucket last week with the appropriate policies for access, and - while the page loaded without the errors seen above - it still wouldn't upload files.

I left it alone over the weekend and when I came back to it today the new bucket works. The old one still doesn't and I can't figure out why, but I'm ok with starting 2021 in a new bucket. Thanks for the help in troubleshooting this.