Impossible to create a mobile broadband connection

[Dario Menin]

On Ubuntu 17.10, from Gnome Control Center, try to create a new broadband connection, the connection is never created and the device is always off.

Tried to debug as described here, by stopping the services and then starting them in debug mode: https://www.freedesktop.org/wiki/Software/ModemManager/Debugging/

NetworkManager log after stopping and restarting ModemManager:

<info> [1520076712.3932] ModemManager disappeared from bus
<info> [1520076712.4212] ModemManager available in the bus
<debug> [1520076723.4620] device[0x5578f118d010] (ttyACM0): constructed (NMDeviceModem)
<debug> [1520076723.4620] device[0x5578f118d010] (ttyACM0): start setup of NMDeviceModem, kernel ifindex 0
<debug> [1520076723.4621] device[0x5578f118d010] (ttyACM0): unmanaged: flags set to [platform-init,!loopback=0x10/0x18/unmanaged/unrealized], set-managed [loopback=0x8])
<debug> [1520076723.4621] device[0x5578f118d010] (ttyACM0): unmanaged: flags set to [platform-init,!loopback,!user-settings=0x10/0x58/unmanaged/unrealized], set-managed [user-settings=0x40])
<debug> [1520076723.4621] device[0x5578f118d010] (ttyACM0): unmanaged: flags set to [!loopback,!platform-init,!user-settings=0x0/0x58/managed/unrealized], set-managed [platform-init=0x10])
<debug> [1520076723.4622] manager: rfkill: WWAN hw-enabled 1 sw-enabled 1
<debug> [1520076723.4622] (ttyACM0): cannot enable/disable modem: initializing or failed
<debug> [1520076723.4622] device[0x5578f118d010] (ttyACM0): unmanaged: flags set to [!sleeping,!loopback,!platform-init,!user-settings=0x0/0x59/managed/unrealized], set-managed [sleeping=0x1])
<info> [1520076723.4629] manager: (ttyACM0): new Broadband device (/org/freedesktop/NetworkManager/Devices/6)
<debug> [1520076723.4632] manager: (ttyACM0): assume: cannot generate connection: device class NMDeviceModem does not support generating a connection
<info> [1520076723.4633] device (ttyACM0): state change: unmanaged -> unavailable (reason 'managed', internal state 'external')
<debug> [1520076723.4633] platform-linux: error reading /proc/sys/net/ipv6/conf/ttyACM0/accept_ra: Failed to open file "/proc/sys/net/ipv6/conf/ttyACM0/accept_ra": File o directory non esistente
<debug> [1520076723.4634] platform-linux: error reading /proc/sys/net/ipv6/conf/ttyACM0/accept_ra_defrtr: Failed to open file "/proc/sys/net/ipv6/conf/ttyACM0/accept_ra_defrtr": File o directory non esistente
<debug> [1520076723.4634] platform-linux: error reading /proc/sys/net/ipv6/conf/ttyACM0/accept_ra_pinfo: Failed to open file "/proc/sys/net/ipv6/conf/ttyACM0/accept_ra_pinfo": File o directory non esistente
<debug> [1520076723.4634] platform-linux: error reading /proc/sys/net/ipv6/conf/ttyACM0/accept_ra_rtr_pref: Failed to open file "/proc/sys/net/ipv6/conf/ttyACM0/accept_ra_rtr_pref": File o directory non esistente
<debug> [1520076723.4634] platform-linux: error reading /proc/sys/net/ipv6/conf/ttyACM0/forwarding: Failed to open file "/proc/sys/net/ipv6/conf/ttyACM0/forwarding": File o directory non esistente
<debug> [1520076723.4635] platform-linux: error reading /proc/sys/net/ipv6/conf/ttyACM0/disable_ipv6: Failed to open file "/proc/sys/net/ipv6/conf/ttyACM0/disable_ipv6": File o directory non esistente
<debug> [1520076723.4635] platform-linux: error reading /proc/sys/net/ipv6/conf/ttyACM0/hop_limit: Failed to open file "/proc/sys/net/ipv6/conf/ttyACM0/hop_limit": File o directory non esistente
<debug> [1520076723.4635] platform-linux: error reading /proc/sys/net/ipv6/conf/ttyACM0/use_tempaddr: Failed to open file "/proc/sys/net/ipv6/conf/ttyACM0/use_tempaddr": File o directory non esistente
<debug> [1520076723.4636] platform-linux: sysctl: failed to open '/proc/sys/net/ipv6/conf/ttyACM0/accept_ra_defrtr': (2) File o directory non esistente
<debug> [1520076723.4636] platform-linux: sysctl: failed to open '/proc/sys/net/ipv6/conf/ttyACM0/accept_ra_pinfo': (2) File o directory non esistente
<debug> [1520076723.4636] platform-linux: sysctl: failed to open '/proc/sys/net/ipv6/conf/ttyACM0/accept_ra_rtr_pref': (2) File o directory non esistente
<debug> [1520076723.4637] platform-linux: sysctl: failed to open '/proc/sys/net/ipv6/conf/ttyACM0/use_tempaddr': (2) File o directory non esistente
<debug> [1520076723.4637] platform-linux: sysctl: failed to open '/proc/sys/net/ipv6/conf/ttyACM0/forwarding': (2) File o directory non esistente
<debug> [1520076723.4637] device[0x5578f118d010] (ttyACM0): bringing up device ignored due to disabled
<debug> [1520076723.4637] device[0x5578f118d010] (ttyACM0): preparing device
<debug> [1520076723.4637] device[0x5578f118d010] (ttyACM0): clearing queued IP4 config change
<debug> [1520076723.4638] device[0x5578f118d010] (ttyACM0): clearing queued IP6 config change
<debug> [1520076723.4638] platform-linux: sysctl: failed to open '/proc/sys/net/ipv6/conf/ttyACM0/accept_ra': (2) File o directory non esistente
<debug> [1520076723.4638] platform-linux: sysctl: failed to open '/proc/sys/net/ipv6/conf/ttyACM0/use_tempaddr': (2) File o directory non esistente
<debug> [1520076723.4638] device[0x5578f118d010] (ttyACM0): ip4-config: update (commit=1, routes-full-sync=1, new-config=(nil))
<debug> [1520076723.4639] device[0x5578f118d010] (ttyACM0): ip6-config: update (commit=1, routes-full-sync=1, new-config=(nil))
<info> [1520076723.4641] device (ttyACM0): modem state 'failed'
<debug> [1520076723.4641] device[0x5578f118d010] (ttyACM0): device not yet available for transition to DISCONNECTED
<info> [1520076723.4643] modem-broadband[ttyACM0]: failed to retrieve SIM object: No SIM object available

ModemManager log:

in attachment