Andrew got burned by the MicroSD counterfeit cards that Chris Marquardt talked about here. Leo says that Andrew bought them on Amazon and he says that Amazon has got to start vetting these vendors to make sure they aren't selling counterfeit or bogus SD cards. The important thing to remember though is "if it sounds too good to be true, it often is." Caviat Emptor.
Andrew has also recently updated his Lenovo Yoga and now his fingerprint reader isn't working. Leo says that sometimes Microsoft's driver updates are hardware specific. So get the current drivers from Lenovo and install them. Chances are, it'll start working again. Update through the Lenovo Vantage/System Update key (F12). It'll update with all the necessary drivers.