We just discovered an issue that has come up on a small number of MDM server installs.
Essentially, when upgrading the MDM Server component to 7.2.1, there may be a small chance that the MDM Server service may not get re-registered correctly. The installer will progress and the server binaries will get installed, but the service will remain unregistered.
As an end user, you will notice that when visiting the enrollment page, an error 500 will be displayed.
Here is a cut and paste from a recently created KB on the matter:
KB #24830 : Error 500 encountered on MDM enrollment page after upgrading to version 7.2.1
After upgrading to LANrev MDM Server 7.2.1, you notice that the "LANrev MDM Server" service is not running and encounter the following error when navigating to https://<servername>/profile/enrollment.mdm:
This XML file does not appear to have any style information associated with it. The document tree is shown below.
Internal server error: could not send/receive data to/from LANrev MDM Server
Issue the following command to re-register the LANrev MDM Server Service: