Something went wrong. Confirm you are using the correct sign-in information and that your organization uses this feature. You can try to do this again or contact your system administrator with the error code 80180026. The device is trying to join Microsoft Entra ID while both MDM automatic enrolment is configured in the tenant and the old Intune PC software client (the pre-MDM agent) is installed locally. The two management stacks conflict and the join is refused.
80180026
Enrolment blocked by the legacy Intune PC agent
What it means
Common causes
MDM automatic enrolment is enabled in Microsoft Entra ID (Mobility (MDM and MAM) > Microsoft Intune).
The legacy Intune PC software client agent is installed on the same Windows machine.
How to fix it
Uninstall the Intune PC software client agent from the computer, then retry the Entra join. This is the right fix — the PC agent is a retired management model.
Alternatively, and only as a temporary measure, set MDM user scope to None under Microsoft Entra ID > Mobility (MDM and MAM) > Microsoft Intune. This disables automatic enrolment for everyone, so treat it as a diagnostic step rather than a solution.