As you work towards onboarding your organization to Co-Management, a significant hurdle for some teams is getting Current. For Co-Management, Windows 10 1709 (released in January 2018) is required. Your organization may be in the process of planning or implementing this update, and, once you are updated and Auto Enrollment is configured, your clients will be automatically enrolled to Co-Management.
The great news is that upgrading Windows 10 is enabled by default! In most cases, upgrade problems are related to AAD tenant configurations that have not been updated. To learn how to update these configurations, check out this documentation.
If, at any point in the process, you need assistance with your Windows 10 upgrade, just use the "request assistance" option at: Microsoft.com/en-us/FastTrack/