Episode 11 of Kekkai Sensen aired on 20 June 2015. One would expect episode 12 (the last episode) to have aired a week later, on 27 June 2015. That... did not happen.
At present (17 Aug 2015), the last episode still hasn't aired. This is hugely abnormal - the last time I recall a delay of this magnitude this happening was when the Tohoku earthquake hit back in March 2011 and delayed the last few episodes of a number of winter 2011 shows.
Why is episode 12 over a month delayed?