Hi
I’ve done a system upgrade from LEAP 42.3 to 15 by using zeldor’s procedure https://zeldor.biz/2018/06/upgrade-opensuse-42-3-to-15-0/.
I have rebooted several times, but can not start any KDE app under elevated privilege. KDESU simply hangs infinitely after providing the root password and pressing enter.
This has already been reported here https://forums.opensuse.org/showthread.php/531213-kdesu-hangs but in my case does not go away.
It is essential to be able to start some kde apps under root, otherwise I won’t be able to use the system.
Any way to debug/solve?
T_H_N
I do not know why you followed that description and not the one on the openSUSE web site: https://en.opensuse.org/SDB:System_upgrade
It may not matter or it may not be the origin of your problem, but using some description from somewhere on the Internet is of course risky and the chance that people here have experience with it might also be doubted.
And “any KDE app” is also a bit vague. Give at least one of those applications so that others can experiment.
After the upgrade to 15 I also had to re-install VirtualBox. It was 5.2.4 or so before and is now on 5.2.12. With that I also got a newer kernel (4.12.14-lp150.12.4-default instead of 4.12.14-lp150.11-default). Now the kdesu problem has gone away. lol!lol!lol!
T_H_N
Congratulations you worked it out! 
But I would say you better go for “official” openSUSE sources (including asking the forums here when you are in doubt) then for some individual. I glanced through the link you gave. There is nothing really wrong there IMO, but the one I linked you to has some more precautions (like, see that your are fully updated before you start the upgrade).
Individual people’s docs often start from their own situation, which might deviate from yours. openSUSE docs are watched and maintained by many users and thus may be better care for more general cases at one side, while at the same time caring for special cases.
In this case,
Looks to me that the reference describes the procedure described in the SDB.
After any upgrade,
It’s good SOP to run “zypper up” to make sure you’ve pulled down all the latest fixes and features.
And, maybe a reboot for good measure.
Am speculating that your Virtualbox kernel upgrade itself probably didn’t directly fix your problem, but maybe as part of that update you did your reboot.
TSU