Since the 6-4-2015 maintenance/update it appears that Canceling a cast will result in the Zone crashing.
I am also still unable to trade a Monke-Onke to Thubu Parohren in Port Windurst, to break the 50 cap.
Also I feel that I'm receiving the 'Lost catch due to skill' to much now.
I was testing things in Qufim Island and when trying to pull in BlueTail I received the 'lost catch due to skill', what i feel, was about 50% or more of the time.
My fishing skill is currently capped at 50. The Bluetail is a 55 skill fish, according to this site -
http://www.great-blue.jp/?fid=039&lng=en Edit - After doing more fishing I may have just had a bad luck bit. I've been reliable catching Bluetail for about an hour now.
I honestly don't remember how frequent often one should get the 'lost catch due to skill' message or how far away from current skill one should get this message though.
Edit:
It does also appear that you lose stackable bait and lures when you cancel a fish.
Stackable bait I know you would lose on cancels. Losing a Lure to a cancel though is new, so not sure if that's intended or not.