Error when attaching 9 USB devices to VirtualHere Client

Hi, I am running VirtualHere Client on Ubuntu 18.04 and Fedora 29. When I try to attach the 9th device, my device gets disconnected.

The following is the error log:


15:49:56 INFO :VirtualHere Client 4.6.2 starting (Compiled: Nov 17 2018 10:08:03)
15:49:56 INFO :Using config at /home/young/.vhui
15:49:56 INFO :IPC available at /tmp/vhclient
15:49:56 INFO :Auto-find using Bonjour - on
15:49:56 INFO :Auto-find using Bonjour SSL - on
15:49:57 INFO :Failed to connect to session manager: SESSION_MANAGER environment variable not defined
15:50:14 ERROR :There are no more available free ports. Try disconnecting an existing device

Could you advise how I can get more than 8 devices working?

Thanks.