Question

I am getting a run-time error “The type initializer for ‘SensionVB.CommonCall’ threw an exception.” when trying instantiate the object call:

Dim general As New SensionVB.CommonCall

When stepping through the code once it hits the above line in code and fails, it does .

The suggestions from Microsoft are to check for null, or add new neither is true in this case

SensionVB = Project
CommonCall = Public Class with various functions

Public Class CommonCall
Protected WithEvents litOne As System.Web.UI.WebControls.Literal
Public Shared sConnection As String = ConfigurationManager.ConnectionStrings("SerialStamperConnectionString").ConnectionString
Public Shared oConnection As New MySqlClient.MySqlConnection(sConnection)
Public Shared sMaxSerialNumber As String = "S000001"
Public Shared bLoggedin As Boolean = False
Public Shared iPageWidth As Integer = 1024

Public Shared isValidPassword As Boolean = False
Public Shared strCompanyID As String = ""
Public Shared strSecurityID As String = ""

Dim Response As New HttpResponse(HttpWriter.Null)
Const TimeOutInMinutes As Integer = 60
Const SiteTitle As String = "SensiOn"
Public Const PageWidth As Integer = 1250
Public SSOenabled As Boolean
Const SuperUserEmails As String = "[e-mail]"
Public Sub Initialize()
    oConnection.Open()
End Sub

Answer 1

I see three lines that may possibly be the culprit:

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Public Shared sConnection As String = ConfigurationManager.ConnectionStrings("SerialStamperConnectionString").ConnectionString

There are several potential issues here. One, your connection string name (“SerialStamperConnectionString”) is incorrect. If this name does not match a key in the web.config, then it will return Nothing, causing a NullReferenceException when you attempt to get the value of the ConnectionString property.

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Public Shared oConnection As New MySqlClient.MySqlConnection(sConnection)

It’s possible that your connection string above is not configured properly in the web.config, thus returning Nothing as the ConnectionString. If sConnection has been set to Nothing, it’s possible that a NullReferenceException could be thrown my the MysqlConnection constructor.

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Dim Response As New HttpResponse(HttpWriter.Null)

If HttpWriter.Null is Nothing then this could also be the source of your problem (for the same reason noted above).

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If none of these suggestions seem to be causing the problem, then I would suggest posting more information about your issue (including the stack trace). Offering a million reputation points will not give us any additional information about your code.

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ADDENDUM
According to the VB documentation on Shared constructors (and, by extension, members):

Exactly when shared constructors are run is mostly implementation dependent, though several guarantees are provided if a shared constructor is explicitly defined:

• Shared constructors are run before any instance of a class type is created.
• Shared constructors are run before any instance members of a structure type are accessed, or before any constructor of a structure type is explicitly called. Calling the implicit parameterless constructor created for structures will not cause the shared constructor to run.
• Shared constructors are run before any of the type’s shared members are referenced.
• Shared constructors are run before any types that derive from the type are loaded.
• A shared constructor will not be run more than once during a single execution of a program.

9.3.2 Shared Constructors

You may find it useful to create a Shared constructor in which to initialize your shared fields:

Public Shared sConnection As String
Public Shared oConnection As MySqlClient.MySqlConnection

Shared Sub New()
    Dim l_connectionString = ConfigurationManager.ConnectionStrings("SerialStamperConnectionString")
    If l_connectionString IsNot Nothing Then
        sConnection = l_connectionString.ConnectionString
        oConnection = New MySqlClient.MySqlConnection(sConnection)
    Else
        ' What to do here?
    End If
End Sub

This will not solve your problem, most likely, but it may make it easier to find and to handle (null string, etc.)