When using the default locking strategy for a case, there is a timeout of 30 minutes. If the user starts and assignment, gets distracted and doesn't come back to save or submit the assignment within 30 minutes their lock will expire. If someone or something (agent) else obtains a lock on the case after that, then the user tries to save or submit, they get the error message: "This operation requires a lock on the object before it can proceed." This error message doesn't let the user know what they need to do next... the end user doesn't know what a lock is or how to get one. The only thing they can do is refresh, which will cause them to loose any changes they have made, this makes sense because whoever got the lock after them may have made changes to the case data. 

The problem is that the end user has no idea that they have a limited amount of time to save their changes before they may lose their work. What is the best way to communicate this to the end user via the UI?

We are running the version 8.3.2 of the Pega Platform.