Object reference not set error when launching Sitecore Path Analyzer

When I try to run Path Analyzer for the first time, I get an error in the MapSelector.cshtml file, line 41: Object reference not set to an instance of an object.

helper.MakeTreeDefinition("TreeDefinitionFilter", fieldsWrapper, selectedTreeDefinitionId.ToString(), mapRootId.ToString());

UPDATE 4/5/2016: Sandip Patel found the actual solution to this problem.  Please read his solution to fix your Sitecore install.

The issue, in my case, was with the mapRootId object.  That parameter is empty when launching the Path Analyzer, so the function that looks for this value finds nothing.  This happens a few lines earlier, on line 32: 

var mapRootId = parametersHelper.GetMapRootId();

The main problem is that GetMapRootId() is retuning a null value from this command, when that param doesn’t exist.  You can see this by decompiling Sitecore.PathAnalyzer.Client.dll.  Instead, what that command should be doing is returning Sitecore.Data.ID.Null.

A quick fix for this is to update your MapSelector.cshtml file’s line 32 to:

var mapRootId = parametersHelper.GetMapRootId() ?? Sitecore.Data.ID.Null;

This is not a great long term solution, since any Sitecore update may replace this change.  However, one would expect that there will be an updated version of this page that does not rely on Silverlight in the future anyways, so this can work as a temporary patch for you.

The full text of the error is:

Server Error in '/' Application.

Object reference not set to an instance of an object.

Description: An unhandled exception occurred.

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.

Source Error: 

Line 39:                     helper.MakeBorder("FieldsWrapper", filterToggleButton, fieldsWrapper =>
Line 40:                     {
Line 41:                         helper.MakeTreeDefinition("TreeDefinitionFilter", fieldsWrapper, selectedTreeDefinitionId.ToString(), mapRootId.ToString());
Line 42:
Line 43:                         helper.MakeDateRange("DateRangeFilter", fieldsWrapper, true, initialStartDate, initialEndDate, datePreset);

Source File:c:\inetpub\Sitecore\Website\sitecore\shell\client\Applications\PathAnalyzer\Common\Layouts\Renderings\MapSelector.cshtml    Line: 41

Stack Trace: 

[NullReferenceException: Object reference not set to an instance of an object.]
   ASP.<>c__DisplayClassa.b__5(String fieldsWrapper) in c:\inetpub\Sitecore\Website\sitecore\shell\client\Applications\PathAnalyzer\Common\Layouts\Renderings\MapSelector.cshtml:41
   Sitecore.PathAnalyzer.Client.Sitecore.Shell.Client.Applications.PathAnalyzer.Common.Layouts.Renderings.Shared.RenderingHelper.MakeBorder(String controlId, String parent, Action`1 nextControl, String isVisible, Boolean usePadding, String contentAlignment) +43
   ASP.<>c__DisplayClassa.b__4(String filterToggleButton) in c:\inetpub\Sitecore\Website\sitecore\shell\client\Applications\PathAnalyzer\Common\Layouts\Renderings\MapSelector.cshtml:39
   Sitecore.PathAnalyzer.Client.Sitecore.Shell.Client.Applications.PathAnalyzer.Common.Layouts.Renderings.Shared.RenderingHelper.MakeDropDownButton(String controlId, String parent, String textDictionaryKey, Boolean showArrow, Action`1 nextControl) +54
   ASP.<>c__DisplayClassa.b__3(String filterToggleButtonColumnPanel) in c:\inetpub\Sitecore\Website\sitecore\shell\client\Applications\PathAnalyzer\Common\Layouts\Renderings\MapSelector.cshtml:37
   Sitecore.PathAnalyzer.Client.Sitecore.Shell.Client.Applications.PathAnalyzer.Common.Layouts.Renderings.Shared.RenderingHelper.MakeColumn(String controlId, String parent, Int32 gridColumns, Action`1 nextControl) +52
   ASP.<>c__DisplayClassa.b__2(String rowPanel) in c:\inetpub\Sitecore\Website\sitecore\shell\client\Applications\PathAnalyzer\Common\Layouts\Renderings\MapSelector.cshtml:36
   Sitecore.PathAnalyzer.Client.Sitecore.Shell.Client.Applications.PathAnalyzer.Common.Layouts.Renderings.Shared.RenderingHelper.MakeRow(String controlId, String parent, Boolean usePadding, Action`1 nextControl) +52
   ASP.<>c__DisplayClassa.b__1(String contentWrapper) in c:\inetpub\Sitecore\Website\sitecore\shell\client\Applications\PathAnalyzer\Common\Layouts\Renderings\MapSelector.cshtml:35
   Sitecore.PathAnalyzer.Client.Sitecore.Shell.Client.Applications.PathAnalyzer.Common.Layouts.Renderings.Shared.RenderingHelper.MakeBorder(String controlId, String parent, Action`1 nextControl, String isVisible, Boolean usePadding, String contentAlignment) +43
   ASP.<>c__DisplayClass8.b__0(TextWriter __razor_helper_writer) in c:\inetpub\Sitecore\Website\sitecore\shell\client\Applications\PathAnalyzer\Common\Layouts\Renderings\MapSelector.cshtml:34
   System.Web.WebPages.WebPageBase.Write(HelperResult result) +85
   ASP._Page_sitecore_shell_client_Applications_PathAnalyzer_Common_Layouts_Renderings_MapSelector_cshtml.Execute() in c:\inetpub\Sitecore\Website\sitecore\shell\client\Applications\PathAnalyzer\Common\Layouts\Renderings\MapSelector.cshtml:18
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy() +234
   System.Web.Mvc.WebViewPage.ExecutePageHierarchy() +123
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage) +121
   System.Web.Mvc.Html.PartialExtensions.Partial(HtmlHelper htmlHelper, String partialViewName, Object model, ViewDataDictionary viewData) +126
   Sitecore.Mvc.Presentation.ViewRenderer.Render(TextWriter writer) +220

[InvalidOperationException: Error while rendering view: '/sitecore/shell/client/Applications/PathAnalyzer/Common/Layouts/Renderings/MapSelector.cshtml' (model: 'Sitecore.Mvc.Presentation.RenderingModel, Sitecore.Mvc').
]
   Sitecore.Mvc.Presentation.ViewRenderer.Render(TextWriter writer) +704
   Sitecore.Mvc.Pipelines.Response.RenderRendering.ExecuteRenderer.Render(Renderer renderer, TextWriter writer, RenderRenderingArgs args) +31
   Sitecore.Mvc.Pipelines.Response.RenderRendering.ExecuteRenderer.Process(RenderRenderingArgs args) +75
   (Object , Object[] ) +74
   Sitecore.Pipelines.CorePipeline.Run(PipelineArgs args) +480
   Sitecore.Mvc.Pipelines.PipelineService.RunPipeline(String pipelineName, TArgs args) +184
   Sitecore.Mvc.Pipelines.Response.RenderPlaceholder.PerformRendering.Render(String placeholderName, TextWriter writer, RenderPlaceholderArgs args) +224
   (Object , Object[] ) +74
   Sitecore.Pipelines.CorePipeline.Run(PipelineArgs args) +480
   Sitecore.Mvc.Pipelines.PipelineService.RunPipeline(String pipelineName, TArgs args) +184
   Sitecore.Mvc.Helpers.SitecoreHelper.Placeholder(String placeholderName) +267
   Sitecore.Web.UI.Controls.Containers.Borders.Border.RenderPlaceHolder(HtmlTextWriter output) +59
   Sitecore.Web.UI.Controls.Containers.Borders.Border.Render(HtmlTextWriter output) +86
   Sitecore.Web.UI.Controls.ComponentBase.Render() +127
   Sitecore.Web.UI.Controls.Containers.Borders.ControlsExtension.Border(Controls controls, Rendering rendering) +112
   ASP._Page_sitecore_shell_client_Business_Component_Library_Layouts_Renderings_Containers_Borders_Border_cshtml.Execute() in c:\inetpub\Sitecore\Website\sitecore\shell\client\Business Component Library\Layouts\Renderings\Containers\Borders\Border.cshtml:4
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy() +235
   System.Web.Mvc.WebViewPage.ExecutePageHierarchy() +124
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage) +122
   System.Web.Mvc.Html.PartialExtensions.Partial(HtmlHelper htmlHelper, String partialViewName, Object model, ViewDataDictionary viewData) +127
   Sitecore.Mvc.Presentation.ViewRenderer.Render(TextWriter writer) +221

[InvalidOperationException: Error while rendering view: '/sitecore/shell/client/Business Component Library/Layouts/Renderings/Containers/Borders/Border.cshtml' (model: 'Sitecore.Mvc.Presentation.RenderingModel, Sitecore.Mvc').
]
   Sitecore.Mvc.Presentation.ViewRenderer.Render(TextWriter writer) +704
   Sitecore.Mvc.Pipelines.Response.RenderRendering.ExecuteRenderer.Render(Renderer renderer, TextWriter writer, RenderRenderingArgs args) +31
   Sitecore.Mvc.Pipelines.Response.RenderRendering.ExecuteRenderer.Process(RenderRenderingArgs args) +75
   (Object , Object[] ) +74
   Sitecore.Pipelines.CorePipeline.Run(PipelineArgs args) +480
   Sitecore.Mvc.Pipelines.PipelineService.RunPipeline(String pipelineName, TArgs args) +184
   Sitecore.Mvc.Pipelines.Response.RenderPlaceholder.PerformRendering.Render(String placeholderName, TextWriter writer, RenderPlaceholderArgs args) +224
   (Object , Object[] ) +74
   Sitecore.Pipelines.CorePipeline.Run(PipelineArgs args) +480
   Sitecore.Mvc.Pipelines.PipelineService.RunPipeline(String pipelineName, TArgs args) +184
   Sitecore.Mvc.Helpers.SitecoreHelper.Placeholder(String placeholderName) +267
   ASP._Page_sitecore_shell_client_Business_Component_Library_Layouts_Renderings_Structures_Substructures_ApplicationContentM_cshtml.Execute() in c:\inetpub\Sitecore\Website\sitecore\shell\client\Business Component Library\Layouts\Renderings\Structures\Substructures\ApplicationContentM.cshtml:7
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy() +235
   System.Web.Mvc.WebViewPage.ExecutePageHierarchy() +124
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage) +122
   System.Web.Mvc.Html.PartialExtensions.Partial(HtmlHelper htmlHelper, String partialViewName, Object model, ViewDataDictionary viewData) +127
   Sitecore.Mvc.Presentation.ViewRenderer.Render(TextWriter writer) +221

[InvalidOperationException: Error while rendering view: '/sitecore/shell/client/Business Component Library/Layouts/Renderings/Structures/Substructures/ApplicationContentM.cshtml' (model: 'Sitecore.Mvc.Presentation.RenderingModel, Sitecore.Mvc').
]
   Sitecore.Mvc.Presentation.ViewRenderer.Render(TextWriter writer) +704
   Sitecore.Mvc.Pipelines.Response.RenderRendering.ExecuteRenderer.Render(Renderer renderer, TextWriter writer, RenderRenderingArgs args) +31
   Sitecore.Mvc.Pipelines.Response.RenderRendering.ExecuteRenderer.Process(RenderRenderingArgs args) +75
   (Object , Object[] ) +74
   Sitecore.Pipelines.CorePipeline.Run(PipelineArgs args) +480
   Sitecore.Mvc.Pipelines.PipelineService.RunPipeline(String pipelineName, TArgs args) +184
   Sitecore.Mvc.Pipelines.Response.RenderPlaceholder.PerformRendering.Render(String placeholderName, TextWriter writer, RenderPlaceholderArgs args) +224
   (Object , Object[] ) +74
   Sitecore.Pipelines.CorePipeline.Run(PipelineArgs args) +480
   Sitecore.Mvc.Pipelines.PipelineService.RunPipeline(String pipelineName, TArgs args) +184
   Sitecore.Mvc.Helpers.SitecoreHelper.Placeholder(String placeholderName) +267
   ASP._Page_sitecore_shell_client_Business_Component_Library_Layouts_Renderings_Structures_Page_Structures_Application_Dashboard_cshtml.Execute() in c:\inetpub\Sitecore\Website\sitecore\shell\client\Business Component Library\Layouts\Renderings\Structures\Page Structures\Application\Dashboard.cshtml:14
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy() +235
   System.Web.Mvc.WebViewPage.ExecutePageHierarchy() +124
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage) +122
   System.Web.Mvc.Html.PartialExtensions.Partial(HtmlHelper htmlHelper, String partialViewName, Object model, ViewDataDictionary viewData) +127
   Sitecore.Mvc.Presentation.ViewRenderer.Render(TextWriter writer) +221

[InvalidOperationException: Error while rendering view: '/sitecore/shell/client/Business Component Library/Layouts/Renderings/Structures/Page Structures/Application/Dashboard.cshtml' (model: 'Sitecore.Mvc.Presentation.RenderingModel, Sitecore.Mvc').
]
   Sitecore.Mvc.Presentation.ViewRenderer.Render(TextWriter writer) +704
   Sitecore.Mvc.Pipelines.Response.RenderRendering.ExecuteRenderer.Render(Renderer renderer, TextWriter writer, RenderRenderingArgs args) +31
   Sitecore.Mvc.Pipelines.Response.RenderRendering.ExecuteRenderer.Process(RenderRenderingArgs args) +75
   (Object , Object[] ) +74
   Sitecore.Pipelines.CorePipeline.Run(PipelineArgs args) +480
   Sitecore.Mvc.Pipelines.PipelineService.RunPipeline(String pipelineName, TArgs args) +184
   Sitecore.Mvc.Pipelines.Response.RenderPlaceholder.PerformRendering.Render(String placeholderName, TextWriter writer, RenderPlaceholderArgs args) +224
   (Object , Object[] ) +74
   Sitecore.Pipelines.CorePipeline.Run(PipelineArgs args) +480
   Sitecore.Mvc.Pipelines.PipelineService.RunPipeline(String pipelineName, TArgs args) +184
   Sitecore.Mvc.Helpers.SitecoreHelper.Placeholder(String placeholderName) +267
   ASP._Page_sitecore_shell_client_Speak_Layouts_Layouts_Speak_Layout_cshtml.Execute() in c:\inetpub\Sitecore\Website\sitecore\shell\client\Speak\Layouts\Layouts\Speak-Layout.cshtml:28
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy() +235
   System.Web.Mvc.WebViewPage.ExecutePageHierarchy() +124
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage) +122
   System.Web.Mvc.Html.PartialExtensions.Partial(HtmlHelper htmlHelper, String partialViewName, Object model, ViewDataDictionary viewData) +127
   Sitecore.Mvc.Presentation.ViewRenderer.Render(TextWriter writer) +221

[InvalidOperationException: Error while rendering view: '/sitecore/shell/client/Speak/Layouts/Layouts/Speak-Layout.cshtml' (model: 'Sitecore.Mvc.Presentation.RenderingModel, Sitecore.Mvc').
]
   Sitecore.Mvc.Presentation.ViewRenderer.Render(TextWriter writer) +704
   Sitecore.Mvc.Pipelines.Response.RenderRendering.ExecuteRenderer.Render(Renderer renderer, TextWriter writer, RenderRenderingArgs args) +31
   Sitecore.Mvc.Pipelines.Response.RenderRendering.ExecuteRenderer.Process(RenderRenderingArgs args) +75
   (Object , Object[] ) +74
   Sitecore.Pipelines.CorePipeline.Run(PipelineArgs args) +480
   Sitecore.Mvc.Pipelines.PipelineService.RunPipeline(String pipelineName, TArgs args) +184
   Sitecore.Mvc.Presentation.RenderingView.Render(ViewContext viewContext, TextWriter writer) +321
   System.Web.Mvc.ViewResultBase.ExecuteResult(ControllerContext context) +365
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList`1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult) +90
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList`1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult) +833
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList`1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult) +833
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultWithFilters(ControllerContext controllerContext, IList`1 filters, ActionResult actionResult) +81
   System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName) +635