First responder <UIView> does not conform to the UIKeyInput protocol.

Recently stopped working due to the error below. This gets called every time a key is pressed, and nothing is added to the textfield on a button press.

```
First responder <UIView: 0x10aa39320; frame = (0 0; 768 225); layer = <CALayer: 0x281d0a5a0>> does not conform to the UIKeyInput protocol.
```