List View Tools tab missing in SharePoint Designer 2013

Follow the steps given in the below link and may be you can solve your problem.

Go to your hive folder:

Then into Template\1033\workflow

and find WSS.ACTIONS

Inside there will be a reference to a custom DLL, find it and remove it and your designer should start working again.

Make sure you take a backup of the file first.

https://sharepoint.stackexchange.com/questions/68769/sharepoint-2010-sharepoint-designer-notification-the-list-of-workflow-actions

Thanks

You can add it manually if that "Web Part Zone" button is greyed out in SP Designer:

<%@Register Tagprefix="WebPartPages" Namespace="Microsoft.SharePoint.WebPartPages" Assembly="Microsoft.SharePoint, Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c"%>


<WebPartPages:SPWebPartManager id="m" runat="Server"/>
<div data-name="WebPartZone">
    <div xmlns:ie="ie">
        <WebPartPages:WebPartZone runat="server" ID="x0e5f5212505f48a9aac43df13eeae4f9" AllowCustomization="True" AllowPersonalization="False" FrameType="TitleBarOnly" LockLayout="True" Orientation="Vertical">
            <ZoneTemplate>
               <!--DC: Replace this comment with default web parts for new pages. -->
            </ZoneTemplate>
        </WebPartPages:WebPartZone>
    </div>
</div>

Source: Microsoft (2015). How to: Add a Web Part zone snipped in SharePoint 2013. https://msdn.microsoft.com/en-us/library/office/jj862341.aspx