I don't know, but when I replaced to x + (walksp / hsp), an error appeared Q^QI thing, line 21 is wrong. Because if you stand, x + sign(hsp) is 0.
try if (!place_meeting, x + (walksp / hsp), y, objground); // that return 1 or -1 for value X but i dont try in my pc, jist my idea
The error is happening since hsp is 0, and dividing by zero is not possible.I don't know, but when I replaced to x + (walksp / hsp), an error appeared Q^Q