Problem with Scheduled BackUps


I've been running scheduled backups to an S3 bucket for over a year on my Virtualmin; for the last few days, I started seeing this error when the backup is running:
Uploading archive to Amazon's S3 service ..
.. upload failed! Empty response to HTTP request

I have tried to do some research about this error, but haven't found out what it means. Can anybody point me in the right direction to solve this?




Is the S3 bucket you are trying to backup to perhaps in a different region, or protected with an ACL ?

No, it's not in a different region or protected. What's even more confusing is, that after a week of sudden failures, the backup ran successfully last night and I didn't even touch anything. This is so weird...

That is odd - perhaps a network issue contacting S3?