The UA-4FX's internal effects function in 44.1kHz and 48kHz sample rates. Due to the processing power required with a higher sample rate of 96kHz, the UA-4FX's effects cannot be used while operating in 96 REC or 96 PLAY sample rates. If you find that the internal effects of the UA-4FX are off and not accessible, disconnect the USB cable from the UA-4FX, set the sample rate on the UA-4FX to 44.1 or 48 and then reconnect the UA-4FX. This will allow the use of the effects again.