PowerShell fails to call a simple function from an ASP.NET DLL

I'm trying to call this really simple .NET 4 function with PowerShell v2. Its definition look like:

Public Shared Function currentSchoolYear() As String Member of NM4.SiteAdmin.Logic.Subscription

Let's add the path to the DLL file containing that function. It's an ASP.NET MVC web application DLL file.

PS > Add-Type -Path C:\xxx\bin\xxxWebApp.dll

Let's try it (FAIL!):

PS >

[NM4.SiteAdmin.Logic.Subscription]::currentSchoolYear()

Exception calling "currentSchoolYear"

with "0" argument(s): "The type

initializer for

'NM4.SiteAdmin.Logic.Subscription'

threw an exception." At line:1 char:54

+ [NM4.SiteAdmin.Logic.Subscription]::currentSchoolYear

<<<< ()

+ CategoryInfo : NotSpecified: (:) [],

MethodInvocationException

+ FullyQualifiedErrorId : DotNetMethodException

Let's observe the class from PowerShell:

PS >

[NM4.SiteAdmin.Logic.Subscription]

IsPublic IsSerial Name

BaseType

-------- -------- ---- -------- True False Subscription

System.Object

Let's observe the function from PowerShell

PS >

[NM4.SiteAdmin.Logic.Subscription]::currentSchoolYear

MemberType : Method

OverloadDefinitions : {static string

currentSchoolYear()} TypeNameOfValue

:

System.Management.Automation.PSMethod

Value : static 开发者_StackOverflowstring

currentSchoolYear() Name

: currentSchoolYear IsInstance

: True

Why oh why? It seems like the doc to me.

I used this command to get more details about the error:

$error | Format-List -force

Which then throwed this more precise example:

System.NullReferenceException: Object
reference not set to an instance of an
object.
at
NM4.SiteAdmin.GlobalFunctions.EstMachineProduction()
in
C:\xxx\Old_App_Code\DataModel\GlobalFunctions.vb:line
17

And I discovered it was a call to the web.config that failed:

Return
ConfigurationManager.ConnectionStrings.Item("test_DBNM4").ConnectionString

DLL files loaded by PowerShell are probably not in their usual web context. I hardcoded a ConnectionString to test it (temporary, not a good security practice), and it's working.

It sounds like an exception in the static constructor OR a type on which NM4.SiteAdmin.Logic.Subscription depends could not be loaded. I'm assuming "C:\xxx\bin\xxxWebApp.dll" and friends aren't in GAC and you're not running from "C:\xxx\bin\" so therefore powershell can't resolve the dependencies. Try running this from "C:\xxx\bin\".