<warn> Could not grab port (usbmisc/cdc-wdm0): 'Cannot add port 'usbmisc/cdc-wdm0', unsupported'

[Enrico Mioso]

Hello!
I am experiencing an interesting issue with a Quectel EC25 modem in an OpenWRt-based system.

Thu Oct 31 08:24:47 2019 daemon.warn [3133]: <warn>  Could not grab port (usbmisc/cdc-wdm0): 'Cannot add port 'usbmisc/cdc-wdm0', unsupported'
Thu Oct 31 08:24:52 2019 daemon.warn [3133]: <warn>  Couldn't build device ids: 'Unsupported subsystem: /sys/bus'

Where may I look for?

thank you very very much guys, sorry for my absence during the merge phase.

Enrico