Jun 20, 2019 16:50:47.278 [0x7feca2248740] ERROR - Error: Unable to set up server: listen: Permission denied (N5boost10wrapexceptINS_6system12system_errorEEE)
I am quite sure there is a port collision with something your already run on your OMV and one of the services plex brings to the table.
Make sure your plex container is stopped.
Open a ssh shell and check the ouput of `netstat -tulpn’ and see if one of this ports is listed:
32400/tcp
3005/tcp
8324/tcp
32469/tcp
1900/udp
32410/udp
32412/udp
32413/udp
32414/udp
The problem is quite easy: one of the ports is already in use. A port can only be bound by one process. This can be sorted out by identifying the service on OMV and assigning a different port for the service OR by creating a docker network (which will result in using a different logical network interface):
MACVLAN: create a macvlan network in docker. It allows to declare a subnet in your network to be used by docker. You can even assign a fixed from this subet to your container. Though, make sure to exclude this subnet from your LANs dhcp server!
BRIDGED: The other option is to use a bridged network and publish ports.