When I enroll my device in MDM I get an error that says, Guided Access App Unavailable. Please Contact Your Administrator.
You will need to remove the app lock profile from the device by going to the Devices tab in Manager, selecting your device, clicking the Inventory tab and then clicking the trash can icon next to the profile with the app lock policy on it.
You will also want to remove the App Lock profile from your enrollment code. Typically only enterprise apps are able to install quick enough to allow the App Lock profile to come through with the enrollment.
Best Practice: Make sure the app included in your profile is on the device before sending the profile to the device.