DCS experienced a minor incident on March 27, 2026 affecting CloudCover365 Services, lasting 89d 22h. The incident has been resolved; the full update timeline is below.
Affected components
Update timeline
- identified Mar 27, 2026, 04:29 PM UTC
We are currently investigating some Exchange Mailbox backups providing the error “The HTTP request was forbidden with client authentication scheme ‘Anonymous’". This is believed to stem from a change to Microsoft's authentication requirements. We will share additional information once we are able.
- identified Mar 31, 2026, 04:30 PM UTC
We have confirmed that the issue is related to Microsoft Incident EX1256020, which is causing intermittent access problems for some users connecting to their Exchange Online mailboxes via certain connection methods. We are actively reviewing potential workarounds and will contact affected customers directly where an interim solution is possible. A further update will be provided on the morning of the 1st of April
- monitoring Mar 31, 2026, 04:30 PM UTC
We have confirmed that the issue is related to Microsoft Incident EX1256020, which is causing intermittent access problems for some users connecting to their Exchange Online mailboxes via certain connection methods. We are actively reviewing potential workarounds and will contact affected customers directly where an interim solution is possible. A further update will be provided on the morning of the 1st of April
- monitoring Apr 01, 2026, 11:22 AM UTC
We are continuing to monitor Microsoft Incident EX1256020, which is causing intermittent access issues for some users connecting to Exchange Online mailboxes via certain connection methods. We are still actively reviewing potential workarounds and will contact affected customers directly if an interim solution becomes available. A further update will be provided on 2nd April if not before.
- monitoring Apr 16, 2026, 01:27 PM UTC
We continue to look into this with our development team. This is identified as a patch that Microsoft released 27th March for Exchange Web Service access, which now requires explicit access at organization and mailbox levels. We are currently looking into a resolution for this. We will share additional information once we are able. Apologies for any inconvenience caused.
- monitoring Apr 20, 2026, 09:51 AM UTC
We continue to look into this with our development team. We are currently looking into a resolution for this, identified as a change from Microsoft. We will share additional information once we are able. Apologies for any inconvenience caused and thank you for your patience here
- monitoring Apr 24, 2026, 04:32 PM UTC
We continue to look into this with our development team. We are currently preparing / creating a fix that should resolve these errors for impacted jobs, A further update will be provided on Monday the 27th of April
- monitoring Apr 28, 2026, 09:05 AM UTC
We continue to look into this with our development team. We are currently preparing / creating a fix that should resolve these errors for impacted jobs,
- monitoring Apr 28, 2026, 09:06 AM UTC
We continue to look into this with our development team. We are currently preparing / creating a fix that should resolve these errors for impacted jobs,
- monitoring May 22, 2026, 01:08 PM UTC
We continue to look into this with our development team. We are currently preparing / creating a fix that should resolve these errors for impacted jobs,
- resolved Jun 25, 2026, 03:26 PM UTC
We are pleased to confirm that a fix has been identified for the Exchange Web Services authentication issue affecting Veeam Backup for Microsoft 365 jobs. This follows the authentication changes introduced by Microsoft's Exchange patch released 27th March 2026, which required explicit EWS access to be configured at both the organisation and mailbox levels. We will be contacting all affected tenants directly to coordinate the remediation. No action is required from you at this stage; we will be in touch with specific details relevant to your environment. We appreciate your patience throughout this investigation and apologise for any disruption caused.