Windows 10 won't boot on El Capitan
So after almost 48 hours of trial and error this is what saved the day.


Boot on recovery mode and csrutil disable
boot back on OSX
Run diskutil list
Find BOOTCAMP from 'diskutil list' and check the ID (the very first number at the start of the line)
sudo gdisk /dev/disk0


now just input those single letters and press Enter each time


r go to the recovery &amp; transformation menu
h create a new hybrid MBR.
ID add partition ID to the MBR.  Your’s may be different! Use what you got from line 4 above.
y if you are asked “Place EFI GPT (0xEE) partition first in MBR (good for GRUB)?”
accept the default MBR hex code of 07
y set the bootable flag
n do not protect more partitions
o print (display) the MBR.
w Recovery/transformation command (write partition table to disk)
y Say yes to question: do you want to proceed.