You may receive the following error when trying to undo last schedule in a program if you scheduled thousands of events: Error: Data could not be saved. Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.
We are currently evaluating this issue and will update this article when we have more information.
Steps to Duplicate
1. Go to Events > search for the affected program 2. Go to the overall program event page > on the left under task select Undo last schedule 3. See that the undo loads for a minute and then the error appears.