Thanks so much for your help! The original loading problem is gone, and I have gotten the plugin connected to my AWS account. However, there is another problem now, which is that the I cannot seem to upload anything to the S3 bucket. I try to add a file, and it says that the file was added successfully, but it is not actually added to the bucket.
This may have to do with the way I have the Amazon permissions configured. I did not give the user full access, because their are multiple buckets in my account that I do not want Download Manager to touch. More details in private reply.
