public void LocalizedValidation_ThrowsInvalidOperationException_When_NoLocalizationExists() { var foo = new IncorrectlyLocalized(); using (SwitchUICulture(CultureInfo.CreateSpecificCulture("en-US"))) { try { runner.IsValid(foo); Assert.Fail("Should have gotten exception"); } catch (InvalidOperationException ex) { Assert.AreEqual( "The resource type 'Castle.Components.Validator.Tests.Messages' does not have a publicly visible static property named 'key_that_does_not_exists'. You probably marked the resources as internal, to fix this change the 'Access modifier' dropdown to 'Public' in the VS resources editor.", ex.Message); } } }