Zero width non joiners

These used to show up in Sublime as just a vertical red line, now they display as <0x200c> highlighted in red so the Indian, Khmer and Farsi files I work on are full of them and I'd like very much to find the setting or what ever changed with an update that caused this change. I realize it's probably just a setting but I'm just a casual user, not a coder, so any help appreciated, thanks.