Hey there! 
Im new here so sorry if I haven't posted in the right section ><
I've been having this problem that my game, League of Legends wouldn't launch, it would take hours to launch when usually it launchs instantly, I got asked their support team for help and did alot of things from putting the .exe in exceptions and changing internet settings and ended up coming to the point to Uninstall the Antivirus.
After uninstalling it, the launcher suddenly started to work. This happened and is happening with Bitdefender 2015 and 2016. I decided to try the 2016 thinking it would work but same thing happening again ._. I REALLY like Bitdefender but I don't understand why it conflicts with League,
I think a few people have had solved this issue aswell by removing their antivirus, but I don't know if its Bitdefender. I tried turning of the Active Virus Control and it took a short time to load, but still didn't go instant o_o.
It would be great if you could help find a solution for this, or a workaround 
If theres any more info you need feel free to ask, I don't really know what else to put in 
Thanks!~ 