I wonder if it's just me or if anyone else couldn't see the shapes in the puzzle today?  There were the faint outlines of about 5 rows at the bottom but the rest was just numbers in a sea of white.  I got round it in the end by covering the whole puzzle in lines and removing them again but I presume it wasn't intentional?

PS I loaded it again, having completed it, and it looks normal.  Now I'm kicking myself that it was probably just a problem at my end and I'm being dopey.