Generally speaking, cheese crumbs become lumps because they melt after the temperature is too high and then are frozen in the refrigerator.
If the cheese is still within the shelf life, there is no mildew and odor, and it can generally continue to be eaten.
However, if the cheese exceeds the shelf life, or does not exceed the shelf life, but it is moldy and smelly, it is considered to have deteriorated and generally cannot be eaten.