better error handling for MC sampler
better error handling for MC sampler

idaholab/raven,idaholab/raven,joshua-cogliati-inl/raven,joshua-cogliati-inl/raven,idaholab/raven,idaholab/raven,joshua-cogliati-inl/raven,joshua-cogliati-inl/raven,joshua-cogliati-inl/raven,joshua-cogliati-inl/raven,idaholab/raven,idaholab/raven,idaholab/raven,joshua-cogliati-inl/raven