Error occurred in deployment step 'Activate Features': Object reference not set to an instance of an object: feature receiver error

Question

I cretaed a Visual web part in SP 2013. It needs a SharePoint list. So wrote below code in web part feature receiver. When I deploy the solution I get error says Error occurred in deployment step 'Activate Features': Object reference not set to an instance of an object. I set ActivateOnDefault="FALSE" and AlwaysForceInstall="TRUE" . Take a look on my feature manifest file.

<Feature xmlns="http://schemas.microsoft.com/sharepoint/" Title="SharePointProject1 Feature1" ActivateOnDefault="FALSE" AlwaysForceInstall="TRUE" Id="8f7163d5-6c65-40d8-9045-8f74192f07d7" ReceiverAssembly="SharePointProject1, Version=1.0.0.0, Culture=neutral, PublicKeyToken=9c2f0c3a8e22f6a0" ReceiverClass="SharePointProject1.Features.Feature1.Feature1EventReceiver" Scope="Site">
  <ElementManifests>
    <ElementManifest Location="VisualWebPart1\Elements.xml" />
    <ElementFile Location="VisualWebPart1\VisualWebPart1.webpart" />
  </ElementManifests>
</Feature>

This is my Feature1EventReceiver code.

SPWeb spWeb = properties.Feature.Parent as SPWeb;
            SPList laptopList = spWeb.Lists["Laptops"];
            if (laptopList != null)
            {
                laptopList.Delete();

            }
            SPListCollection lists = spWeb.Lists;
            lists.Add("Laptops", "The Laptops", SPListTemplateType.GenericList);
            laptopList = spWeb.Lists["Laptops"];


            laptopList.Fields.Add("Name", SPFieldType.Text, true);
            laptopList.Fields.Add("Model", SPFieldType.Text, true);
            laptopList.Fields.Add("Image", SPFieldType.URL, false);

I can deploy if I have only below code

 SPWeb spWeb = properties.Feature.Parent as SPWeb;

Answer 1

The visual web part should be included to the Site-scoped feature, as a result properties.Feature.Parent is a SPSite object. You need to check feature scope and use the code below if the scope is site.

SPSite site = properties.Feature.Parent as SPSite;
if (site != null){
    SPWeb web = site.RootWeb;
    SPList laptopList = web.Lists["Laptops"];
    ...
}

Answer 2

web.lists[] will cause an exception if the list is not there.

use TryGetList instead

Answer 3

Worked for me after Changed the feature scope level from Site to Web