If you were using a template for the graph, made changes to the view and tried to leave the view without saving the changes, QPR Metrics inquires if you would like to save the current settings to the template or not.
If you choose to save the settings, the Graph view will change accordingly with all elements utilizing the template. Answer Yes, if this is what you want to happen.
If you want to leave the view without saving the changes to the template, answer No. If you do not want to lose the settings but not to save them either as they are now, click Cancel. This will allow you to make the desired modifications to the view before saving them.
For more information on templates, please see the Graph Tab of the Element Properties Window.