It has nothing to do with bogus fingerprint sensors. Rather it has to do with matching fingerprint sensor and logic board. If you buy two identical iphones, and swap their screens (with fingerprint sensors attached), the phones will give this error and become unusuable. Even though both phones have 100% genuine and untampered with fingerprint sensors.
This detail is important - it has nothing to do with authenticity or security of the fingerprint sensor. In theory, the original fingerprint sensor could be tampered with and it would not throw this error. The error only comes up there the phone detects that a fingerprint sensor different from the original one is attached to the logic board.