Upgrade from 16.04 to 16.10 to 17.04 and my UMTS modem would not connect. Creating an empty /etc/NetworkManager/conf.d/10-globally-managed-devices.conf solved my problem.
$ nmcli device show GENERAL.DEVICE: ttyACM0 GENERAL.TYPE: gsm GENERAL.HWADDR: (unknown) GENERAL.MTU: 0 GENERAL.STATE: 100 (connected) GENERAL.CONNECTION: *edited* GENERAL.CON-PATH: /org/freedesktop/NetworkManager/ActiveConnection/3 IP4.ADDRESS[1]: *edited*/28 IP4.GATEWAY: *edited* IP4.DNS[1]: *edited* IP4.DNS[2]: *edited*
Upgrade from 16.04 to 16.10 to 17.04 and my UMTS modem would not connect. Creating an empty /etc/NetworkMan ager/conf. d/10-globally- managed- devices. conf solved my problem.
$ nmcli device show p/NetworkManage r/ActiveConnect ion/3
GENERAL.DEVICE: ttyACM0
GENERAL.TYPE: gsm
GENERAL.HWADDR: (unknown)
GENERAL.MTU: 0
GENERAL.STATE: 100 (connected)
GENERAL.CONNECTION: *edited*
GENERAL.CON-PATH: /org/freedeskto
IP4.ADDRESS[1]: *edited*/28
IP4.GATEWAY: *edited*
IP4.DNS[1]: *edited*
IP4.DNS[2]: *edited*