I had accidentally used if(keyboard_check_pressed(ord(1)) { } instead of if(keyboard_check_pressed(ord("1")) { } and that was causing a whole mess of problems for me strangely. Could be a similar problem, also could not. Good luck!
Edit: ord(1) works perfectly fine in the windows .exe, only caused problems in HTML
Edit2: Also, it turns out when exporting to HTML5, if you've used any draw_text(), the font needs to be included in the project, and set using draw_set_font(). Which is not the case in Windows.