Archive to Amazon S3 fails with
An exception has been thrown, The difference between the request time and the current time is too large, The remote server returned an error: (403) Forbidden
The reason for this failure is that Amazon S3 allows only a small time stamp variation of up to 15 minutes between the server and its requesting client. Since Amazon is a big backup server of a large number of users, it is a security feature.
Synchronization of time between the server and requesting client is very important to have an access to S3.
1.adjust the core's system time to accurate to the real time and ensure it's set to the right time zone.
2.after doing this stop the appassure core service. then start the appassure core service.
3.try a new archive.
If this doesn't work then search for event ids 47 and 37 in the core system event logs. If it says that it's received valid time from the domain controller, then search the domain controller event logs for the event ids. The entries will be under time-service, you'll find that they are out of sync by more than 15 mins.