the saved model will not save the ML solution, that is, it only represents the structure of the model, but not the paramter values. There are two solutions: You can just reload your data set, too, and send it to the model again (by right-clicking on the data set and choosing „send data to model“). The previous parameter results should be saved in the model, so the estimation will be really quick (as it starts on what is the ‚best‘ solution). Alternatively, you can save the „summary estimate“; if you right-click on the model and choose „show estimate summary“, it opens the frame with all the results in text format; you can then right-click on that frame and choose „save script“ to save this text, and later open it with a text editor.
Hope that helps!