JUst a side - note - may well not be a bug but intentional.
The drop rate for the scrolls is clearly not even.
Since the event has begun all the trades have been asking for scroll 4.
As of today there were AT LEAST 100+ trades asking for scroll 4 and NONE asking for anything else (and I stopped at screen 128 it could be going on for hundreds and hundreds of pages.
ALL those trades are Scroll 1 & 5 offers for 4. So scroll 2 is obviously also short today.
It's not statistically possible for the same scroll to be short for EVERY day of the event, with such an ENOURMOUS SKEW, when people are hitting thousands of BG's (over a small sample you might get skewed results - bit not when you roll the dice thousands of times).
Don't know why Plarium would do that - just to mess with people's heads for no sensible reason? To make people do even more loss making BG's, lose more troops and hopefully spend money reviving before they can get full sets? Seriously uncool.