Aftership Returns Center currently requires WS-I compliance (in Magento Core API Settings) be enabled in order to correctly communicate and retrieve order information from the front-end webpage. Returns Center will not successfully locate an order if WS-I compliance is not enabled and gives no indication that this is indeed the reason why - it requires external testing with Returns Center support.
The problem is that majority of third party services interacting with Magento API do not use WS-I compliance, as it is not the default setting for an out-of-the-box store. Enabling WS-I compliancy to make Magento 1 work with Returns Center breaks compatibility with pre-existing third party services, in my case, which is not an option.
Official request to add an option to toggle the WS-I Compliance mode like several other third party services already offer. Thanks.