Use the Cut and not Opaque option, do to the eyelashes. You still only get one sided material though, I use Amplify Shader to create my own double sided Opacity mask shader. If you do not have amplify shader for Unity I do really recommend it.

If you are trying, a Model that was Remeshed with Character Creator 3 there is no Opacity mask image.It was left out, for now.

For those that haven't solved this yet (I keep getting questions about this issue) one workaround is to drag your texture folder into the project first, then drag in the character. Fix the normals with the popup and it should have all textures with no issues. If you don't see a texture folder then drag the fbx file into 3DXchange, 3DS Max or some program that will automatically extract the texture folder for you. Hopefully, this will answer the question for those that search the forum for this problem. I have no idea if this solves all missing texture problems but it has so far for my projects.

EDIT: I should add this does not work on all projects as I have had projects sent to me that failed to show the "Fix Normals" popup. If you don't get that first then I'd try the other workarounds listed in this thread. 

Retired Digital Freelancer, Author, and Die Hard Animator No Longer Under Adult Supervision.
Doing what I want to do... instead of what someone else's script forces me to do.
Writer and reviewer at Reallusion Magazine