OK I'm done. Don't have problem with this event, can clear it completely.



Ninjax ; Doing as Sound said should fix your problem.
I didn't experience any bug, but I wipe out all gift in growth progess.

Since all done I'll farm the event map, considering it give 6 life-crystal / 56 stamina.
It's better than run 16-5 whale stage and get only 5 life-crystal (random) / 100 stamina.
Maybe I can reach 4k life-crystal before next maint, and I really need it badly.