Make the following changes in the TestingModule.csproj file.
<IISUrl>http://localhost/DNN/desktopmodules/TestingModule</IISUrl>
<IISAppRootUrl>http://localhost/DNN/</IISAppRootUrl>
<ProjectExtensions>
<VisualStudio>
<FlavorProperties GUID="{31-65df-11da-9384-00065123321}">
<WebProjectProperties>
<UseIIS>True</UseIIS>
<AutoAssignPort>False</AutoAssignPort>
<DevelopmentServerPort>0</DevelopmentServerPort>
<DevelopmentServerVPath>
</DevelopmentServerVPath>
<IISUrl>http://localhost/DNN/desktopmodules/TestingModule</IISUrl>
<OverrideIISAppRootUrl>True</OverrideIISAppRootUrl>
<IISAppRootUrl>http://localhost/DNN/</IISAppRootUrl>
<NTLMAuthentication>False</NTLMAuthentication>
<UseCustomServer>False</UseCustomServer>
<CustomServerUrl>
</CustomServerUrl>
<SaveServerSettingsInUserFile>False</SaveServerSettingsInUserFile>
</WebProjectProperties>
</FlavorProperties>
</VisualStudio>
</ProjectExtensions>