If your files has no audio it must be a routing issue:
For detailed information, please refer to the X32/M32 console’s User Manual, and its instructions for routing audio in and out of the console.
The uTrack-X32 can record from, and playback to, various channels in your mixing console:
To select the audio channels that you plan to record, go to the console’s menu “Routing” / “Card Out”.
For example, to record the X32/M32 console’s analog inputs, select “Expansion card outputs 1-8” to “local 1-8”, and so on.
To configure the playback channels, go to the console’s menu “Routing” / “Home“.
For example, to playback from USB harddisk to the mixing console’s local analog inputs, select “input 1-8” to “card 1-8”, and so on.
Once you have the recordings on the USB drive use the uTool import function to make mono files from the multichannel wav files