Organizations will enter information such as event goals, event name, etc. when creating a new form or event or they may go back and update that information in the properties for that form or event. In this case the organization receives an Unexpected Error Message when trying to save this information.
This usually occurs when there is a piece of information the system doesn't see as valid. This could include adding a dollar sign or commas to numbers for the event goals, etc or the addition of some types of custom coding.