The error message ECOM00203 translates to “S3 Download error”
When you submit jobs to us via an Amazon S3 location, it's imperative that we can read it. Please refer to the Knowledge Base article on setting permissions if your source file is to be encoded properly. http://edchelp.wpengine.com/idx.php/9/025/Amazon-S3-Integration/article/How-can-I-use-a-Amazon-S3-file-as-a-source.html