** I am having the exact same problem. The WC Amazon S3 plugin been working now for 6 months w/o issues. I made no changes on the credentials or the site, so perhaps it is an S3 issue, but I want to find someone to help on it in case it is not.
PROBLEM = same as this person's issue:
I have an Amazon S3 account. I have a WooCommerce store. I use the WooCommerce Amazon S3 plugin to serve downloads from the S3 account.
I need an expert in AWS / S3 to sort this out.
***My error message is different, obviously, since I have a different site, but it is essentially the same as this person***
This is the error message:
Error parsing the X-Amz-Credential parameter; the region 'us-east-1' is wrong; expecting 'us-west-2'