why wont it let me draw the cross at the gargoyles .ive tried and tried and it wont go yellow .ive tried drawing the cross like starting at top but no joy

Try posting in the Hints and Help forum, I recall have some issues at this point as well. In my case I'd either neglected to complete something or didn't have the correct items.

The pentagram was a real challenge for me because I played it using a mouse pad.