It looks like you are probably referencing the original scenario with your call Scn = scenario(Prj, “All Models”), rather than the Results Scenario that contains the output associated with this original scenario. Each original scenario can spawn multiple results scenarios – i.e. one for each time you run the original scenario. Only the Results Scenarios contain output.
Try the command scenario(Prj) to see a list all your scenarios, including all the Results Scenarios. From here you can get the ID for the result scenario and then use the command Scn = scenario(Prj, ScnID), where ScnID is the unique ID for the appropriate Results Scenario.