The USB connection indicator is blinking.

■ If the USB/MIDI indicator is blinking
The dedicated driver software is not installed on the PC/Mac. To input/output audio to/from the PC/Mac, download the driver software from [here] and install it.
For details, see [PC/Mac setup] in the Instruction Manual.

■ If the MULTI I/O indicator is blinking
An unsupported mobile device is connected.
Look up a list of compatible mobile devices [here].

You can read the Instruction Manual [here].