I read in the discussion, that some players are experiencing the same problem despite updating the app. I tried to check level 700 and it still doesn't work.
You are right, this level has been reported many times by players. They should be able to fix the problem as soon as possible. I advise you not to waste boosters or gold bars until it is fixed.
You are absolutely right! I love your challenges because I love art in all its genres. I really like all the creations of the players because they have expressed themselves and this is beautiful. Of course I will participate in your next challenge! π