Yes, the array is big enough, it's been sized for 256 entries, and entries after that one are fine.
I've just deleted the line and retyped it, and now it's working. I wonder if maybe some odd invisible characters had got stuck onto the line, as it was part of a copy and paste operation. Before that, none of the suggestions were working either, and when I replaced "//" with "a", that also caused my game to exit out immediately. Very odd.
Anyway, problem solved for the time being
