LoadComplete displays this message when you are trying to edit a load shape, but the needed settings are not defined in your test. The Custom shape workload profile requires that the Continuous load setting be enabled in your test and that you define some duration for it. Without defining test duration the load shape workload cannot be edited and simulated.
Click Yes in the message box to accept the changes suggested by LoadComplete and set the duration to 1 hour. You can also click No and specify the desired test duration any time later on the Continuous Load tab of the Load Test editor.
For more information on using the “Custom shape” workload, see Defining Workload Profile.
For more information on using continuous load, see Setting The Overall Test Duration.