I recently installed the latest version of MtoA (5.2.0) and of Cryptomatte for Nuke (1.2.2 on GitHub).
It renders the Cryptomatte perfectly and I can see them in Nuke. But in the Cryptomatte node, when I try to pick a color, it doesn't add it to the Matte list, even if I force the update.
I had a very old version of MtoA and Cryptomatte since I didn't work with it since a very long time, that's why I updated all of this.
I'm on Maya 2018 and Nuke 11 (Non-Commercial).
Thank you very much