This error may occurs after hasw1 has been rebooted. It indicates that the CanBus module hasn't been correctly loaded.
User action: Exit ONLINE and try to re-load the module with
Unixsudo /usr/local/bin/can_reload
Start ONLINE again and try something like:
ONLINEgofoil 10
If this command results in the same error, repeat the procedure. The only good thing is: Once the module has been correctly loaded, it works until the next re-boot.