I had similar problems with CC hair.
I'm a novice here so follow my advice only if you have a back up plan. ")

I almost didn't want to reply my advice here as it includes deleting stuff. So make sure the 1st thing you do is make back ups.

Do you still have the zip file for the hair?
Try deleting the actual runtime files, then decompress & reload it again. I believe I had to replace the hair in my scene so if you have edits to it you will lose them. Did you make those back ups yet. ;)

I can't explain why this is but at 1st I had to bring the trancparency in Materials down or up & back again for it to even show in preview correctly.
I thought I had it solved then when like two renders away from completing my last scene my hair went back to what you are getting in your pic.

I think it is a P6 thing. I'm thinking the hair was created for a previous version. I'm also a novice so maybe others can add something here.

I hope this works for you but more so I hope it doesn't put you further back. Again I am new at this to.

Good Luck!

Scott