This is normal. The transmitter is warning you that hazardous switch settings are present, and that you should change them before you transmit. It's to prevent flying a model in a condition that may make it difficult, if not impossible to control. You have to reset the switch, and then cycle the power. Remember to let the transmitter fully shut down before turning it back on.

If you turn off the mix before selecting the "Yes" to continue, the screen changes to the "Transmit? Yes/No" screen. You can then select "Yes" and get ready to start up.