That's short for "not a number (indefinite)". Looks like another bug.
I can't make a save because I don't have an account however, I tested it and when you put protons or electrons, the one with 142 is blue on heat mode. It works with other elements too, but not all of them (I can't replicate it with EXOT, PHOT, GLOW or static solids(It works with GOO and moving SPNG))
@jacob1
what about server scripts?it does not work?
Maybe it's the client cannot convert the data into a table