As previously announced in MC1035701 (March ’25), we’re upgrading OneNote’s sync infrastructure to deliver improved security, performance, and reliability across all supported platforms ― including OneNote for Windows, Mac, iOS, Android, and OneNote for Windows 10. To benefit from these enhancements, users must be on the latest version of OneNote.

[When this will happen:]

The rollout completed at the end of June 2025

[How this affects your organization:]

Users on older versions of OneNote may experience sync interruptions, including:

• Notebooks opening as read-only with a “Refresh” prompt
• Messages like “Saved offline C Refresh”
• Sync error messages with code E000006C (cig68)

These issues will persist until users update their apps or click the “Refresh” prompt. This behavior is expected as we transition to the new sync infrastructure.

[What you can do to prepare:]

1. Recommended: Ensure all users are on the latest version of OneNote to enable a seamless transition with no disruption.
2. Support users on older builds: If immediate updates aren’t possible, users can continue using OneNote, but sync behavior will vary:

Refer affected users to the following Microsoft Support article for troubleshooting guidance Fix issues when you can’t sync OneNote.

Impacted platforms: All OneNote platforms are affected:

• OneNote for Windows
• OneNote for Mac
• OneNote for iOS
• OneNote for Android
• OneNote Online
• OneNote for Windows 10 (Note: this app reaches end of support in October 2025)

For additional support, contact your Microsoft support team or use Help > Support within OneNote on Windows.