If the Show advanced model equation controls options in components Advanced Project option is active, the Always create state checkbox is shown on Control components that can be configured with the input as as state variable to match an extra error equation added by other control or scheduling components. With this option active, a state is always added to the model to ensure the same equation set is used in a case regardless of the component being active or not (for numerical stability reasons or in cases where the model is externally controlled using the GSP API). This setting usually needs to be accompanied by a Always create error option set in a component adding an error equation.
Always Create State
