When upgrading Kentico project to Visual Studio 2013, you may get the following error on PortalTemplate page.
Error:
Server Error in '/' Application.
________________________________________
Value cannot be null.
Parameter name: key
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.ArgumentNullException: Value cannot be null.
Parameter name: key
Source Error:
Line 9: <asp:Literal runat="server" ID="tags" EnableViewState="false" />
Line 10: </head>
Line 11: <body class="<%=BodyClass%>" <%=BodyParameters%>>
Line 12: <form id="form" runat="server">
Line 13: <asp:PlaceHolder runat="server" ID="plcManagers">
Source File: c:\PROJECTS\Website\Website-Vs2013\Cms\Source\CmsSite\CMSPages\PortalTemplate.aspx Line: 11
Fix:
There are two workarounds at the moment:
1. Not using "Browser link" feature in Visual Studio.
2. Use the following key in your web.config file:
<appSettings>
<add key="PageInspector:ServerCodeMappingSupport" value="Disabled" />
</appSettings>
