Google announced that they will stop providing the Realtime API capabilities for Google Drive files to third party applications (such as MindMup) soon. MindMup used that capability to save maps until recently, and since July we allow users to store maps in an alternative format that will keep working after December 2018. In preparation for the change, users who saved maps to Google Drive will start seeing notifications to convert them into the new format.
We have now published a page intended for end-users that clarifies the changes and actions they might need to take. You can read it here https://www.mindmup.com/tutorials/google-realtime-deprecation-faq.html.
Domain administrators can share this page with their users to proactively explain what will happen over the next few months. For privacy reasons, we have not previously stored information on individuals accessing MindMup via Google Drive with organisational accounts, so we’re unable to notify your users directly.