Z2 No Sound From Any Ouptputs

My system set up:

Kontrol Z2 mixer

2 - CDJ 2000 Nexus 2

Kontrol F1

Traktor Scratch 2.11.3.17

Macbook Pro (2017) OS 10.12.6 (Sierra) 3.1 GHz Intel core i7, 16GB ram, 2 TB SSD

I have been using this setup for 4 years with XDJ1000 mk1. Recently I upgraded to CDJ2000 NXS2. I tested my system extensively at home and worked perfect. I have then performed at quite a few events, again worked perfectly.

This past weekend, I traveled to a destination 8 hours away from home. When I arrived and set up, I had no audio output from any output. No sound was coming from the main outputs, no sound from booth output, no sound from headphones. When I moved faders or knobs, there was movement on the computer screen. The computer showed it was sending audio out when I played music. The mixer channel LED strip was lit up showing audio passing though the mixer, but the master out LED light strip was not lighting up no matter where the volume was set. All audio routing was correct in the settings. I changed USB cables. I eliminated the powered hub and went directly to the computer and there was no sound. I restarted the computer, I turned the computer off and on. Everything was powered off and turned back on and still no sound.

I plugged a USB drive in to the CDJ, unplugged the Z2 from the computer and attempted to use it as a stand alone mixer, again, there was no sound output.

When I came home yesterday, I plugged everything in powered it up and now everything appears to be working. Can someone tell me why this happened? What do I need to look for? How can I fix this if this happens again? I spent 2 hours troubleshooting before I gave up and had to use a back up system.

 

I am experiencing the exact same problem. Zero output from either main or booth. Headphones working for cue though. Traktor software seeing signals and displaying them. I have attempted to use the mixer as a standalone and play vinyl directly through phono input with phone selected on mixer and usb not connected to computer. Zero output.

I will post anything learned more about this problem, please do the same. Peace

Setup:
Traktor Z2 running newest firmware 42 with 51 installed
Tractor Pro 3 - 3.3. 0 108
Mac running Catalina 10.15.5 (but using the Z2 only as a stand alone)
Techniques SL1200's
XLR cables out to Alesis M1 Active Studio Monitors