I have diyHue running on a Pi 3B+ in Raspbian with deCONZ and everything was working well (with Yeelights, Hue Lights/switches, IKEA Lights/switches, etc.).
Today I had to do a regular reboot and after that the hue-emulator.service is no longer working, systemctl says “activating” for a while and then “failed”. Restarting the service doesn’t help. I have no idea how to troubleshoot this and have no control over my lights, any ideas?
Update: I also did an uninstall of diyHue, a reboot and a reinstall, but the service still won’t start.
Please provide the debug output. Manually start the emulator with additional argument --debug
sudo ./HueEmulator3.py --debug
Thank you for the reply. I have already uninstalled diyHue and did a docker install, so I can’t debug my problem anymore. I imported the config.json from the previous installation and everything works again, the same as before. I do hope the docker installation won’t also fail after a reboot in the future, but so far so good 
I am not sure if docker has the mqtt implementation yet. But the library issue is fixed now upon install stage.
I’m not sure what the mqtt implementation means or what the library issue is or was?
Since moving to a docker installation, I can no longer connect to the diyHue bridge with the official Hue app because it doesn’t register clicking the “Activate” button. In Hue Essentials it does. Does this have anything to do with that? Other than that (and a Timezone problem) I haven’t noticed a difference so far.