Suddenly my USB mobile broadband modem has stopped working and is completely unable to connect. I have done nothing, so it's surely some recent update of some network/modem related package (probably modemmanager or network-manager or god knows) that is completely broken and shamefully has been releases without proper testing.
What is most properly the package responsible for this? Is it modemmanager, or some modem driver in which case how do I figure out which one? My modem is a Huawei K3565 Rev 2 (12d1:140c). It used to work "fine" (except for the handful of bugs that make one's life a hell, but i could always connect to the internet), now there's no way to connect.
Once I have figured out which package it is, how do I "undo" recent updates and manually go back to a working version? No way I wait until they fix this; it will take ages, and it was working.
ok If you feel like due to updates its broken , then you can restore it to its born. Depending upon your arch of PC download the proper package of network-manager from here Ubuntu-package
Then install with
sudo dpkg -i filename.deband say yes to install.