Check that you have not deselected microphone signals, or lowed said signals to 0.You can reset the sound output in Kontakt Player by navigating to the Output option > clicking on the dropdown 'Preset's/ Batch Configuration > Batch Functions > Clear output section and create one individual channel for each loaded instrument. If you have multiple MIDI inputs, either via Software or Hardware, it's always good to change the MIDI channel to 'Omni', incase your keyboard is not attached to Port A - Channel 1 (the default channel selected).
Additionally, check your hardware is on, and working, if you are using an audio interface and monitors. Prior to following the steps below, check your audio preferences are connected to the right output and make sure your MIDI track channel isn't muted.
