I had a issue with Docker today. One Docker container became unresponsive after I tried to update the config. I hanged in the browser. So I tried to remove the container and this was impossible then I stopped the other containers. My intention was to stop and start docker again. This didn't help. So then I tried to stop the array. This also failed and unRAID server OS generated a report with graceful shutdown. After everything rebooted my virtual network of Docker was gone. I had to change some network settings and apply to rewrite the network config I guess. After that everything worked again. So I suspect that it has something to do with a disappearing / crashing virtual network... So to be clear my Docker container have a own ip address. I hope you guys can use this information.
Attached the report.