SP 2007 - Webpart cannot be displayed

Question

Error: "A Webpart on this Page cannot be displayed or imported. The type could not be found or it is not registered as safe"

Trying to find the details of this error in source-code but not quite sure where the exact problem is located.

refer to This Thread for previous fixes performed.

Any pointers on a good location to start?

DLL: TCBOE.ChartPart.dll

Namespace: TCBOE.Chartpart

FeatureReceiver.vb

Private Shared Sub AddOrRemoveChartHandlerToWebConfig(ByVal web As SPWebApplication, ByVal remove As Boolean)
    Dim asm As String = String.Format(CultureInfo.InvariantCulture, _
      "System.Web.UI.DataVisualization.Charting.ChartHttpHandler, System.Web.DataVisualization, Version={0}, Culture=neutral, PublicKeyToken={1}", _
      New Object() {"3.5.0.0", "31bf3856ad364e35"})
    Dim modif As New SPWebConfigModification("add[@path='ChartImg.axd']", _
      "configuration/system.web/httpHandlers")
    modif.Owner = "TCBOE.ChartPart"
    modif.Sequence = 0
    modif.Type = SPWebConfigModification.SPWebConfigModificationType.EnsureChildNode

    modif.Value = String.Format(CultureInfo.InvariantCulture, _
      "<add verb=""{0}"" path=""{1}"" type=""{2}"" validate=""{3}"" />", _
      New Object() {"GET,HEAD,POST", "ChartImg.axd", asm, "false"})
    If (remove) Then
        web.WebConfigModifications.Remove(modif)
    Else
        web.WebConfigModifications.Add(modif)
    End If

End Sub
Private Shared Sub AddOrRemoveChartSettingsToWebConfig(ByVal web As SPWebApplication, ByVal remove As Boolean)
    Dim appSettings As New SPWebConfigModification("appSettings", "configuration")
    appSettings.Owner = "TCBOE.ChartPart"
    appSettings.Sequence = 0
    web.WebConfigModifications.Add(appSettings)

    Dim keyVal As String = String.Format(CultureInfo.InvariantCulture, _
     "storage={0};timeout={1};", _
     New Object() {"memory", "20"})
    Dim modif As New SPWebConfigModification("add[@key='ChartImageHandler']", "configuration/appSettings")
    modif.Owner = "TCBOE.ChartPart"
    modif.Sequence = 1
    modif.Type = SPWebConfigModification.SPWebConfigModificationType.EnsureChildNode

    modif.Value = String.Format(CultureInfo.InvariantCulture, _
      "<add key=""{0}"" value=""{1}"" />", _
      New Object() {"ChartImageHandler", keyVal})
    If remove Then
        web.WebConfigModifications.Remove(modif)
    Else
        web.WebConfigModifications.Add(modif)
    End If
End Sub
<SharePointPermission(System.Security.Permissions.SecurityAction.Demand, ObjectModel:=True)> _
Public Overrides Sub FeatureActivated(ByVal properties As Microsoft.SharePoint.SPFeatureReceiverProperties)
    Dim site As SPSite = TryCast(properties.Feature.Parent, SPSite)
    Dim web As SPWebApplication = site.WebApplication
    AddOrRemoveChartSettingsToWebConfig(web, False)
    AddOrRemoveChartHandlerToWebConfig(web, False)
    web.Farm.Services.GetValue(Of SPWebService)().ApplyWebConfigModifications()
    web.Update()
End Sub
<SharePointPermission(System.Security.Permissions.SecurityAction.Demand, ObjectModel:=True)> _
Public Overrides Sub FeatureDeactivating(ByVal properties As Microsoft.SharePoint.SPFeatureReceiverProperties)
    Dim site As SPSite = TryCast(properties.Feature.Parent, SPSite)
    Dim web As SPWebApplication = site.WebApplication
    AddOrRemoveChartSettingsToWebConfig(web, True)
    AddOrRemoveChartHandlerToWebConfig(web, True)
    web.Farm.Services.GetValue(Of SPWebService)().ApplyWebConfigModifications()
    web.Update()
End Sub

---

Added: 10/26/2011 @ 11:36am

Manifest.xml

(As created by WSPBuilder)

<?xml version="1.0"?>
<!-- Solution created by WSPBuilder. 10/26/2011 8:19:40 AM  -->
<Solution SolutionId="ee03c5c2-c9bd-4cfe-ac16-225f8e28072b" xmlns="http://schemas.microsoft.com/sharepoint/">
  <Assemblies>
    <Assembly Location="cablib.dll" DeploymentTarget="GlobalAssemblyCache" />
    <Assembly Location="TCBOE.ChartPart.dll" DeploymentTarget="GlobalAssemblyCache">
      <SafeControls>
        <SafeControl Assembly="TCBOE.ChartPart, Version=3.5.1.0, Culture=neutral, PublicKeyToken=9f4da00116c38ec5" Namespace="TCBOE.ChartPart" TypeName="*" Safe="True" />
      </SafeControls>
    </Assembly>
  </Assemblies>
  <TemplateFiles>
    <TemplateFile Location="IMAGES\ChartPartWP\oscillator_16.gif" />
    <TemplateFile Location="IMAGES\ChartPartWP\oscillator_32.gif" />
  </TemplateFiles>
  <FeatureManifests>
    <FeatureManifest Location="ChartPartWP\feature.xml" />
  </FeatureManifests>
</Solution>

Are there any situations where a CAS policy would restrict a local-machine user account (used to run services) would cause this kind of behaviour?

Edit 11/3/2011:

Ok finally got a "Great Practices" install and it is stable and working. Got the original control i am customizing to load and working as it should.

Went to go "install" my edited control and received this error response when trying to deploy the solution:

Feature '47d62f5e-b0e0-4f93-bcd1-081ca794527c' could not be installed because the loading of event receiver assembly "TCBOE.ChartPart, Verstion=3.5.1.0, Culture=neutral, PublicKeyToken=9f4da00116c38ec5" failed: System.IO.FileNotFoundException: Could not load file or assembly 'TCBOE.ChartPart, Culture=neutral, PublicKeyToken=9f4da00116c38ec5' or one of its dependencies. The system cannot find the file specified. 
File name: 'TCBOE.ChartPart, Culture=neutral, PublicKeyToken=9f4da00116c38ec5' 
   at System.Reflection.Assembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, Assembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection) 
   at System.Reflection.Assembly.InternalLoad(AssemblyName assemblyRef, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection) 
   at System.Reflection.Assembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection) 
   at System.Reflection.Assembly.Load(String assemblyString) 
   at Microsoft.SharePoint.Administration.SPFeatureDefinition.get_ReceiverObject() 

WRN: Assembly binding logging is turned OFF. 
To enable assembly bind failure logging, set the registry value [HKLM\Software\Microsoft\Fusion!EnableLog] (DWORD) to 1. 
Note: There is some performance penalty associated with assembly bind failure logging. 
To turn this feature off, remove the registry value [HKLM\Software\Microsoft\Fusion!EnableLog].

Answer 1

The web part should be registered in web.config's SafeControls. It's very simple to do. Try the following link:

http://msdn.microsoft.com/en-us/library/ms581321(v=office.12).aspx

Answer 2

Are you using an usercontrol to render the webpart? If so, put this on the top of your UserControl:

<%@ Assembly Name="System.Web.DataVisualization, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" %>

If you are not using an UserControl, just modify your code to add that line to your web.config inside the tag:

<add assembly="System.Web.DataVisualization, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />

I told you this back in the other thread, you are doing the ultra-hard mode way trying to fiddle with this stuff by hand. If you were using SmartPart or VSeWSS 1.3 you would not go through all this.