Backups to S3 are failing (3.65Pro + S3 Europe)

I have just setup a new Amazon EC2 instance with a Virtalmin Pro license. It is running 3.65Pro

Every time I a backup to a European S3 bucket I get the following email:

Creating backup for virtual server annecharnock.com ..

Copying virtual server configuration ..
.. done

Backing up Cron jobs ..
.. none defined.

Creating TAR file of home directory ..
.. done

Copying Apache virtual host configuration ..
.. done

Copying Logrotate configuration ..
.. done

Dumping MySQL database annecharnock ..
.. done

Backing up AWstats configuration file ..
.. done

Creating backup for virtual server omniwiki.co.uk ..

Copying virtual server configuration ..
.. done

Backing up Cron jobs ..
.. done

Creating TAR file of home directory ..
.. done

Copying Apache virtual host configuration ..
.. done

Copying Webalizer configuration files ..
.. done

Copying SSL Apache virtual host configuration and certificate ..
.. done

Copying Logrotate configuration ..
.. no log rotation configuration found!

Backing up AWstats configuration file ..
.. done

Creating backup for virtual server goingcarbonneutral.co.uk ..

Copying virtual server configuration ..
.. done

Backing up Cron jobs ..
.. none defined.

Creating TAR file of home directory ..
.. done

Copying Apache virtual host configuration ..
.. done

Copying Logrotate configuration ..
.. done

Dumping MySQL database goingcarbonneutral ..
.. done

Backing up AWstats configuration file ..
.. done

Creating backup for virtual server oilfieldreview.com ..

Copying virtual server configuration ..
.. done

Backing up Cron jobs ..
.. none defined.

Creating TAR file of home directory ..
.. done

Copying Apache virtual host configuration ..
.. done

Copying Logrotate configuration ..
.. done

Dumping MySQL database oilfieldreview ..
.. done

Backing up Webmin ACL files ..
.. done

Backing up AWstats configuration file ..
.. done

Backing up bootup actions ..
.. none found

Creating backup for virtual server carbonleapfrog.org ..

Copying virtual server configuration ..
.. done

Backing up Cron jobs ..
.. none defined.

Creating TAR file of home directory ..
.. done

Copying Apache virtual host configuration ..
.. done

Copying Webalizer configuration files ..
.. done

Copying Logrotate configuration ..
.. done

Dumping MySQL database carbonleapfrog ..
.. done

Backing up AWstats configuration file ..
.. done

Backing up Virtualmin settings (Module configuration, Server templates, Reseller accounts, New mailbox email messages, Custom fields, links and shells, Third-party script installers, Third-party content styles, Scheduled Virtualmin backups) ..
.. done

Creating final backup archive ..
.. done

Uploading archive to Amazon's S3 service ..
.. upload failed! Missing Location header

Backup failed! See the progress output above for the reason why. Total backup time was 18 minutes, 05 seconds.

Sent by Virtualmin at: https://MY.DOMAIN.HERE:10000

As you can see, the backup is failing. I have another server which is running 3.64Pro (and is backing up to USA S3 buckets) which does not have this problem.

This is a major problem for me as I rely on these backups to bring my EC2 instances up.

Status: 
Closed (fixed)