Moq + Unit Testing - System.Reflection.TargetParameterCountException: Parameter count mismatch

Question

I\'m tring to use a lambda with a multiple-params function but Moq throws this exception at runtime when I attempt to call the mock.Object.Convert(value, null, null, n

Answer 1

Not an answer for OP but perhaps for future googlers:

I had a Callback that didn't match the signature of the method being setup

Mock
    .Setup(r => r.GetNextCustomerNumber(It.IsAny()))
    .Returns(AccountCounter++)
    .Callback(badStringParam, leadingDigit =>
    {
        // Doing stuff here, note that the 'GetNextCustomerNumber' signature is a single int 
        // but the callback unreasonably expects an additional string parameter.
    });

This was the result of some refactoring and the refactoring tool of course couldn't realise that the Callback signature was incorrect