Error: "400 Bad request error" - The query string "fileName" is missing or invalid

Datto SaaS Protection backups can experience a partial failure when attempting to backup a site or list attachment file containing an unsupported character. This primarily impacts M365 Teams and SharePoint services.

Environment

• Datto SaaS Protection 2.0 for Microsoft 365

Cause

This error occurs when a site or list attachment file contains an unsupported special character.

Resolution

Remove any unsupported special characters from attachment file and run the backup again.

List of supported special characters

The following special characters are supported: