Hi,
Clover.NET uses the static constructor (.cctor) of the class to initialize some internal field that NCover uses to gather information.
Your code mocks Procedure static constructor and thus
Clover.NET throws the Exception.
In order to bypass this make sure that you let the static constructors run (unmocked) as follows:
MockObject procedureMock = MockManager.MockObject(typeof(Procedure,Constructor.StaticNotMocked));
:idea: I will add a requirement to support
Clover.NET linkage when static constuctors are mocked