Error on Activate Features on deploying SharePoint Skin

Question

Error occurred in deployment step 'Activate Features': Object reference not set to an instance of an object. I just can't figure out where the error is occuring. Found some blog posts concerning the issue but they weren't really helpful either.

public class Feature1EventReceiver : SPFeatureReceiver
{
    // Uncomment the method below to handle the event raised after a feature has been activated.

    public override void FeatureActivated(SPFeatureReceiverProperties properties)
    {
        SPSite parent = (SPSite)properties.Feature.Parent;
        SPFeatureProperty property = properties.Feature.Properties["MasterPage"];
        string str = property.Value;
        SPFeatureProperty property2 = properties.Feature.Properties["SearchMasterPage"];
        string str2 = property2.Value;
        if (!string.IsNullOrEmpty(str))
        {
            str = SPUrlUtility.CombineUrl(parent.ServerRelativeUrl, "_catalogs/masterpage/" + str);
            str2 = SPUrlUtility.CombineUrl(parent.ServerRelativeUrl, "_catalogs/masterpage/" + str2);
            foreach (SPWeb web in parent.AllWebs)
            {
                if (((web.WebTemplate == "SRCHCENTERLITE") || (web.WebTemplate == "SRCHCEN")) || (web.WebTemplate == "SRCHCENTERFAST"))
                {
                    web.MasterUrl = str;
                    web.CustomMasterUrl = str2;
                }
                else
                {
                    web.MasterUrl = str;
                    web.CustomMasterUrl = str;
                }
                web.Update();
            }
        }

    }


    // Uncomment the method below to handle the event raised before a feature is deactivated.
    public override void FeatureDeactivating(SPFeatureReceiverProperties properties)
    {
        SPSite parent = (SPSite) properties.Feature.Parent;
        string str = SPUrlUtility.CombineUrl(parent.ServerRelativeUrl, "_catalogs/masterpage/v4.master");
        string str2 = SPUrlUtility.CombineUrl(parent.ServerRelativeUrl, "_catalogs/masterpage/minimal.master");
        foreach (SPWeb web in parent.AllWebs)
        {
            if (((web.WebTemplate == "SRCHCENTERLITE") || (web.WebTemplate == "SRCHCEN")) || (web.WebTemplate == "SRCHCENTERFAST"))
            {
                web.CustomMasterUrl = str2;
            }
            else
            {
                web.MasterUrl = str;
                web.CustomMasterUrl = str;
            }
            web.Update();
        }
        SPListCollection lists = parent.RootWeb.Lists;
        SPList list = lists["Metro UI Themes"];
        lists.Delete(list.ID);

    }

Answer 1

Do you know what line exactly it's erroring out on? You may be able to find this in the logs, or at least a better idea of where it's breaking. If I had to guess I'd say it's not finding one of the master pages. Have you tried switching this line:

if (!string.IsNullOrEmpty(str))

To this:

if (!string.IsNullOrEmpty(str) && !string.IsNullOrEmpty(str2))