How do I disable|reset the fingerprint scanner on the nexus 6p? It doesn't work properly since I restored my twrp backup from my old 6p (this one is a replacement). I'd like to remove the fingerprints so I can reset the whole thing, how can I do that?

When I turn on my screen, I also get a litte message which says:

Fingerprint hardware not available


P.S. I'm rooted in case that helps.

edit: To clarify, I can get past the lockscreen, but deleting the fingerprints in the settings doesn't do anything, they're not being deleted.
I've solved this problem by deleting /data/fpc/ and the fpdata folders in the folders in /data/system/users/.