Errore nell'installazione di EntityframeworkwithheirarchyId6.0.2

Ciao, ho un problema con l'installazione di entityframeworkwithheirarchyId come posso risolverlo. Ho installato e reinstallato qualche volta ma non funziona.

       Exception calling "LoadFrom" with "1" argument(s): "Could not load file or assembly                                   `EntityFramework.PowerShell.Utility, 
       Version=6.0.0.0, Culture=neutral, PublicKeyToken=6847f3395fc61b47' or one of its           dependencies. Strong name validation fai
led. (Exception from HRESULT: 0x8013141A)"
At D:\ 2012\Projects\ClassLibrary1\packages\EntityFrameworkWithHierarchyId.6.0.2\tools\EntityFramework.psm1:669 char:62
+     $utilityAssembly = [System.Reflection.Assembly]::LoadFrom <<<< ((Join-Path $ToolsPath EntityFramework.PowerShell.Ut
ility.dll))
    + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
    + FullyQualifiedErrorId : DotNetMethodException

You cannot call a method on a null-valued expression.
At D:\ 2012\Projects\ClassLibrary1\packages\EntityFrameworkWithHierarchyId.6.0.2\tools\EntityFramework.psm1:670 char:50
+     $dispatcher = $utilityAssembly.CreateInstance <<<< (
    + CategoryInfo          : InvalidOperation: (CreateInstance:String) [], RuntimeException
    + FullyQualifiedErrorId : InvokeMethodOnNull

Exception calling "CreateInstanceFrom" with "8" argument(s): "Could not load file or assembly 'EntityFramework.PowerShell
, Version=6.0.0.0, Culture=neutral, PublicKeyToken=6847f3395fc61b47' or one of its dependencies. Strong name signature co
uld not be verified.  The assembly may have been tampered with, or it was delay signed but not fully signed with the corr
ect private key. (Exception from HRESULT: 0x80131045)"
At D:\ 2012\Projects\ClassLibrary1\packages\EntityFrameworkWithHierarchyId.6.0.2\tools\EntityFramework.psm1:698 char:31
+     $domain.CreateInstanceFrom <<<< (
    + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
    + FullyQualifiedErrorId : DotNetMethodException

Exception calling "LoadFrom" with "1" argument(s): "Could not load file or assembly 'EntityFramework.PowerShell.Utility, 
Version=6.0.0.0, Culture=neutral, PublicKeyToken=6847f3395fc61b47' or one of its dependencies. Strong name validation fai
led. (Exception from HRESULT: 0x8013141A)"
At D:\ 2012\Projects\ClassLibrary1\packages\EntityFrameworkWithHierarchyId.6.0.2\tools\EntityFramework.psm1:669 char:62
+     $utilityAssembly = [System.Reflection.Assembly]::LoadFrom <<<< ((Join-Path $ToolsPath EntityFramework.PowerShell.Ut
ility.dll))
    + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
    + FullyQualifiedErrorId : DotNetMethodException

You cannot call a method on a null-valued expression.
At D:\ 2012\Projects\ClassLibrary1\packages\EntityFrameworkWithHierarchyId.6.0.2\tools\EntityFramework.psm1:670 char:50
+     $dispatcher = $utilityAssembly.CreateInstance <<<< (
    + CategoryInfo          : InvalidOperation: (CreateInstance:String) [], RuntimeException
    + FullyQualifiedErrorId : InvokeMethodOnNull

Exception calling "CreateInstanceFrom" with "8" argument(s): "Could not load file or assembly 'EntityFramework.PowerShell
, Version=6.0.0.0, Culture=neutral, PublicKeyToken=6847f3395fc61b47' or one of its dependencies. Strong name signature co
uld not be verified.  The assembly may have been tampered with, or it was delay signed but not fully signed with the corr
ect private key. (Exception from HRESULT: 0x80131045)"
At D:\ 2012\Projects\ClassLibrary1\packages\EntityFrameworkWithHierarchyId.6.0.2\tools\EntityFramework.psm1:698 char:31
+     $domain.CreateInstanceFrom <<<< (
    + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
    + FullyQualifiedErrorId : DotNetMethodException

cosa devo fare per risolvere questo problema? Voglio avere un dato gerarchico quindi problema nella configurazione di questo per favore aiutami.