Cannot Back up. Native Multipart Upload Must Be Enabled for This Backup Format (code 2519)

Situation

A backup plan terminates with the following error: Native multipart upload is disabled. Cannot back up. Native multipart upload must be enabled for this backup format

Cause

The new backup format requires using native multipart upload for S3-compatible storage destinations. Most probably, you have the native multipart upload disabled in your storage account settings.

Solution

Enable native multipart upload. To do this, proceed as follows:

1. In the application menu, select Edit Storage Accounts.
2. Find the required one, then click Edit.
3. On the Storage Account tab, click Advanced Settings.
4. In the Advanced Settings property box, select the Use native multipart upload (recommended) check box.

5. Click OK.
6. Run the backup plan again.