Some more testing:
- Tried booting with mga4 kernel - No difference
- Turned off "Manage by Networkmanager" and reboot: Then it works

So it seems like the supplied version of Networkmanager does the
wrong things.

Also just found that "systemctl disable networkmanager" doesn't disable it for all users. Had to rename the binary.... Sigh...

@ Dag Nygren,

Sorry for the very late reply. We are short on active BugSquad members.

Could you please attach /root/drakx/report.bug from the time of the upgrade? (It'll need to be compressed, first)

It is unlikely that you still have log files from right after upgrading, but if that doesn't give an nearly empty file, then please do also attach journal.txt that is the result of running, as root:

    journalctl --since=2015-07-12 --until=2015-07-13 > journal.txt

Keywords: (none) => NEEDINFO
CC: (none) => marja11
Assignee: bugsquad => mageiatools

It is really more than a year ago and the logs have been cleaned out a long time ago, so unfortunately I cannot provide either of them. But I can verify that Networkmanager is still not able to connect to an "Ad-Hoc" wireless station.
Killing Networkmanager and resorting to drakconf the connection will work.

(In reply to Dag Nygren from comment #4)
> It is really more than a year ago and the logs have been cleaned out a long
> time ago, so unfortunately I cannot provide either of them. But I can verify
> that Networkmanager is still not able to connect to an "Ad-Hoc" wireless
> station.
> Killing Networkmanager and resorting to drakconf the connection will work.

So I had assigned wrongly :-(

Anyway, thank you, Dag Nygren, for having taken the needed time to report this issue and update the report!

Did this bug get fixed? If so, please change its status to RESOLVED - FIXED

If it didn't, then we regret that we weren't able to fix it in Mageia 5. Mageia 5 has officially reached its End of Life on December 31st, 2017 https://blog.mageia.org/en/2017/11/07/mageia-5-eol-postponed/
It only continued to get important security updates since then, because we were waiting for the big Plasma5 update in Mageia 6, that fixed many of the Mageia 5 => 6 upgrade issues.

If you haven't seen that this bug got fixed, then please check whether this bug still exists in Mageia 6. If it does, then please change the Version (near the top, at the left) to "6". If you know it exists in Cauldron, then change Version to Cauldron. If you see it in both Cauldron and Mageia 6, then please set Version to Cauldron and add MGA6TOO on the Whiteboard.

Thanks,
Marja

(In case this report needs to stay open for a supported release: 
Reassigning to the gnome maintainers, since NetworkManager is a Gnome tool.
CC'ing the base system maintainers, because it has "Group: System/Base")

Assignee: mageiatools => gnome
Source RPM: (none) => networkmanager
Component: Release (media or process) => RPM Packages
CC: sysadmin-bugs => basesystem

No reply, so closing as OLD since Mageia 5 is no longer maintained.

Resolution: (none) => OLD
Status: NEW => RESOLVED