AssignFeaturePackToSiteSubscription Throws Error.

Hello Guys,

I am creating feature pack using server object model. When I am assigning this feature pack to site subsription I m getting error like,.Specified argument was out of the range of valid values.  Here I am updating my code. I am getting error on last line of code thats

 mgr.AssignFeaturePackToSiteSubscription(fs, subscription);

SPSecurity.RunWithElevatedPrivileges(delegate
                {
                using (var site = new SPSite("http://spf2013dev1:3001/sites/TestSite2"))
                {
                    SPSiteSubscription subscription = site.SiteSubscription;
                    SPSiteSubscriptionSettingsManager mgr = SPSiteSubscriptionSettingsManager.Local;
                    SPSiteSubscriptionFeaturePackCollection fSec = mgr.GetAllFeaturePacks();
                    SPSiteSubscriptionFeaturePack fs = mgr.CreateFeaturePack();
                    SPFeatureDefinitionCollection fDefs = SPFarm.Local.FeatureDefinitions;
                    SPFeatureDefinition fd = null;
                    fd = fDefs[new Guid("09ce0902-ef5c-45da-b727-a76e7f551607")];
                    fs.Add(fd);
                    mgr.AssignFeaturePackToSiteSubscription(fs, subscription);
                }
            }
            );

If you have any clue where exactly I am wrong, please let me know your comments.

Thanks in Advance.