Problem with AWS Elemental MediaLive Workflow Wizard

I'm getting some errors when I try to do a live stream using MediaLive. In MediaLive, I have MP4 input (stored in public s3) and MediaPackage configured as the destination. I created three end-points for MediaPackage (HLS, DASH, and CMAF). I used MediaLive Workflow Wizard to configure/set up the workflow as shown below:

When I started the workflow, I got the following alerts from MediaLive Channel:

Also when I tried to open the HLS playlist or DASH MPD, I got a 404 error.

For debugging purposes, I've given full access to the IAM role that is associated with the channel.

Any idea on what I'm missing?