Why is my touch id not working

So I've recently replaced my iPhone 6 screen, and since then my touch id has not been working. I go into the password/touch id settings and it shows that I have no fingers registered, and when i try to register my finger, a "Failed, Unable to complete Touch ID setup. Please go back and try again" error pops up. This is happened in the past when I've replaced my screen, but now I'm not going to ignore it. I have already reset my phone to factory default and it still didn't work