Caught Exception: Request has expired. Timestamp date: 2015-04-28T19:53:50.000Z
Response Status Code: 400
Error Code: RequestExpired
Error Type: Sender
Request ID: xxxxxxxxxxxxx
XML:


Sender
RequestExpired
Request has expired. Timestamp date: 2015-04-28T19:53:50.000Z

xxxxxxxxx


ResponseHeaderMetadata: RequestId: 5ff6d1af-4771-4faa-a2f4-3e94e0ef2c6e, ResponseContext: euQHnCvC2n+3xrNmxRmA0nXlxcRKJhk+EOCqEA7946ru5JWPV+zdDJyF1ZK5K7oq6wyD+2YdoJ4=, Timestamp: 2015-04-29T02:37:49.911Z, Quota Max: , Quota Remaining: , Quota Resets At:


How to fix?

Check the server time of amazon MWS server time at:
https://mws.amazonservices.com/

The Timestamp attribute must contain the client’s machine time in ISO8601 format; requests with a timestamp significantly
different (15 minutes) than the receiving machine’s clock will be rejected to help prevent replay attacks.

sometimes, it is your server’s time is not correct. you can fix this by doing:
$ ntpdate ntp.ubuntu.com