Settings.Default.Save() does not persist when debugging app in Visual Studio

Question

I have some code that is intended to determine if a setting already exists and get the value if it does.

            exists = Settings.Default.Properties.OfType<SettingsProperty>().Any(p => p.Name == "LastOpenLocation");
        if (!exists)
        {
            SettingsProperty lastOpenLocation = new SettingsProperty("LastOpenLocation");
            lastOpenLocation.PropertyType = typeof(string);
            lastOpenLocation.DefaultValue = casMate.OpenPath;
            Settings.Default.Properties.Add(lastOpenLocation);
            Settings.Default.Save();
        }
        else
        {
            Settings.Default.Properties["LastOpenLocation"].DefaultValue = casMate.OpenPath;
        }

Everything runs fine with no exceptions. The next debug run the settings saves last time do not persist. I want to make sure that settings are persisting before installing the app on production machines. What is the issue? Why do my settings not persist between debug runs?

Answer 1

The answer to this question is... A stack answer I couldn't find initially

I am trying to create a new setting at run time. New settings can only be created at design time.