If you used a version of OptQuest earlier than 11.1.1.x, be aware of some significant changes. As you have discovered, the user interface is redesigned to be easier to use. For added flexibility, there are now five types of decision variables.
Another difference is that .opt files are no longer used to store optimization settings. For more information on saving optimization settings and options, see Saving Optimization Models and Settings. An .opt file viewer is provided to help you transfer settings from .opt files to current model workbooks. For instructions, see Transferring Settings from .opt Files.