In Diagrams Options go to General options > System configuration > AutoSave. There are two options available Auto Save and Auto Save Interval (Mins).

By default, the Auto Save option is False and Auto Save Interval (Mins) is disabled. When the Auto Save option is set to True the Auto Save Interval (Mins) is enabled.

The minimum time interval required for Auto Save diagrams is 1 minute and the maximum time interval required is 120 minutes. If a value higher than 120 minutes is entered it is rounded off automatically to 120 (maximum interval). If a value lower than 1 is entered it ise rounded off automatically to 1 (minimum time interval). By default, the option is set to 10 minutes. When the Auto Save option is False, the Auto Save Time Interval option will be disabled.

To start Auto Save set the option Auto Save to True and also set the time interval.

If the time interval has come to an end and there are still changes to be made the Auto Save will go into a hold state. When work is completed the Auto Save will save the work automatically.

When the option Auto Save is set to False, the time interval option is disabled and the application works as previously.