Network Manager is unable to connect to Wifi. Ask password and then loop forever

[openfred]

On Live session or after installation, the wifi adapter is recognized, the password phrase is accepted but it never connect and loop forever.

Thinkpad T430 with Intel Centrino 6205
03:00.0 Network controller: Intel Corporation Centrino Advanced-N 6205 [Taylor Peak] (rev 34)

It is not a Passphrase issue. Same PC with Debian 9 or 10 works very well.
Really strange, considering Ubuntu 18.04 is based on Debian 10 !!!

After comparing many files, it appears that the 2 last lines of /etc/NetworkManager/NetworkManager.conf have been added on Ubuntu !

Debian 10:
    $ cat /NetworkManager/NetworkManager.conf
    [main]
    plugins=ifupdown,keyfile

    [ifupdown]
    managed=false

Ubuntu 18.04:
    $ cat /etc/NetworkManager/NetworkManager.conf
    [main]
    plugins=ifupdown,keyfile

    [ifupdown]
    managed=false

    [device]
    wifi.scan-rand-mac-address=no

I removed the last 2 files in Ubuntu 18.04, and now Wifi works perfectly. The wifi passphrase is accepted, and even going to sleep mode and back is fine.

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I would strongly recommend to modify /etc/NetworkManager/NetworkManager.conf in package network-manager to remove the 2 last lines.
In fact this file should not be modified by Ubuntu and kept as in Debian.
Is it possible to do it in Ubuntu before 18.04 LTS to be launched ???
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It seems this 2 lines have been added due to bug 1681513:
https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/1681513
As reported here:
https://askubuntu.com/questions/905283/wifi-issue-with-ubuntu-17-04

By the way, file NetworkManager.conf is empty in Fedora...

Cheers
Fred

[Sebastien Bacher (seb128)]

There is only one report and it doesn't seem like a release concern at this point even if it would be interesting to investigate. The mac-address option doesn't sound like it should have an effect, could you try if just restarting network-manager without changing the config has the same impact?

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.