How to reconfigure obsolete server connections that use Basic Authentication in CodeTwo Backup
Problem:
After updating CodeTwo Backup to the new version, some connections are marked as [obsolete] and there is a permanent alert shown on the Bad news card that reads:
Server connection '{Connection displayname}' needs to be reconfigured to use Modern Authentication (OAuth 2.0) when connecting to Microsoft 365. Otherwise, jobs that use this connection will stop working when Basic Authentication is disabled for your tenant.A similar message is displayed when you run a job that uses an obsolete connection.
Solution:
Starting with version 2.3.x for Exchange Online and version 2.4.x for SharePoint Online, CodeTwo Backup no longer uses Basic Authentication. Instead, it uses Modern Authentication (OAuth 2.0). This means you need to register the backup app in Microsoft Entra ID (Azure Active Directory) for the tenant you want to connect to.
There are a few reasons for this change. First, Modern Authentication is more secure. Second, Microsoft disabled legacy authentication in Exchange Online as of January 2023 and in SharePoint Online as of May 1, 2026.
Server connections marked as [obsolete], as shown in Fig. 1., are connections to Exchange Online and SharePoint Online created in the previous versions of CodeTwo Backup that use Basic Authentication. You can no longer create such connections – you can only reconfigure them to use Modern Authentication.
Important
Jobs that use obsolete server connections will still work and can be used to back up or restore your Microsoft 365 data. However, they will continue to work only until Basic Auth is enabled. When Basic Authentication is disabled (either permanently by Microsoft or manually on your server), you will not be able to access that server with CodeTwo Backup by using obsolete connections.
Server connections to on-premises Exchange and SharePoint servers still use Basic Authentication in CodeTwo Backup. They are not marked as [obsolete] and don’t require to be reconfigured.
CodeTwo Backup shows notifications regarding obsolete server connections in different places of the Administration Panel to remind you to reconfigure them as soon as possible. That way, you can make sure that the program will continue backing up your data even after Basic Authentication has been disabled.
To reconfigure an obsolete server connection, go to the Dashboard tab, click the Manage (
) button on the Defined server connections card, select a connection marked as [obsolete] and click Edit (Fig. 1.).
Fig. 1. Selecting an obsolete server connection for editing.
A new server connection wizard will open. Use the links below to open a step-by-step guide on how to reconfigure a connection to:
Tip
You can disable all alerts informing about the use of an obsolete server connection in CodeTwo Backup, but it is not recommended. Instead, you should reconfigure these connections to use Modern Authentication to ensure uninterrupted backups.
To disable these alerts, click Notification options () on the Bad news card and clear the checkbox to the left of Obsolete connection in use (Fig. 2.).
Fig. 2. Disabling the notifications regarding the use of obsolete server connections.
| Related products: | CodeTwo Backup for Exchange, CodeTwo Backup for Office 365 |
| Categories: | FAQ |
| Last modified: | May 5, 2026 |
| Created: | June 24, 2020 |
| ID: | 875 |
