After replacing an iPhone 6 screen the touch ID is unresponsive.

Otherwise, it's a hardware issue. Usually what happens is that the flex cable tears or the Home Button Link cable (the one that goes underneath the LCD shield plate) is damaged during the repair. Perhaps just one pin was damaged so you will need to inspect it closely, preferably under magnification.

If you don't see any hardware issues, you could try to do a hard reset of the device first (Home & Power buttons for 10 sec). If that doesn't solve it, you could try to do a full restore (backup your device, reset the device and then restore) or even do a full DFU restore. That will eliminate any potential software/iOS issues.

Yeah it just really weird cause typically the phone will tell you if touch id isn't there. But I have done a hard reset. I didn't try to do a software update or anything else. After talking to the customer the customer told me that she had been already experiencing issues with the home button not working sometime. I failed to check it when she initially got here(Shame on me). So I just took responaibility for it and only charged half price. I will email her and see if she can try a software update. Thankd for the extra information. i have been doing repairs for over 3 years and have never seen this.