screen locking - where to turn it off?

I have just ubgraded KDE4 to Plasma5 on my i586 computer since all the other computers now run plasma5. After a few minutes of inactivity the screen locked and even though I took great care to give the right password it didn’t unlock. Now I don’t really need screen locking here and I want to turn it off. So I went to System Settings → Desktop Behaviour → Screen locking. But there is no way to turnh off the screen locking completely. The only settings are: Lock screen after: with a maximum of 99 minutes (no never!) the next field is Require Password after locking with a maximum setting of of 300sec (Does that mean after the screen is locked for 300 sec the password is no longer working??? or what???). Then there is a tickbox with the writing Lock screen on resume (what does that mean? when I want to resume working?) and then I can change the Background. Nothing else.
Now I use opensuse since version 9.2 but I never came across such strange settings. Where can I turn off the screen locking - possibly in a config file? Further the System settings have no screen settings any more - only compositor settings for desktop effects under Display and Monitor. None of my other 4 computers in the network has these strange settings and required settings missing.
Cheers
Uli

I found the file kscreenlockerrc which contains the settings in the menu I described. Here it is:

uli@linux-dfsr:~/.config> more kscreenlockerrc 
[Daemon]
LockGrace=300
LockOnResume=false
Timeout=99

[Greeter]
Theme=org.openSUSE.desktop
uli@linux-dfsr:~/.config>

I just wonder whether “Timeout=never” would do?

Did you try systemsettings5? Not systemsettings.

@Sauerland: I’ve been struggling with similar issues and your tip did the trick. Thanx

Note: I’d only noticed the issue on PCs updated from 13.2. No issue on 2 with fresh installs of Leap

What I used was systemsettings5 but the old menu with screen settings and screen locker is systemsettings although I didn’t see it in the menu. I thought the upgrade to Plasma5 may have missed a package. Like caprus I didn’t have this problem with leap but with the 13.2 upgrade. Thanks Sauerland.

To complete the upgrade repair I had to right click on Application Launcher, select Edit Applications> Settings > Configure Desktop and then change the entry in the Command Window to systemsettings5. I didn’t take the time to figure out how to edit the entry in Favorites. I just deleted the old one and then right clicked on the new icon under Settings and selected Add To Favorites to replace it.

To confirm that the repair was successful just click on each icon to open Configure Desktop then click on Version. If the version is 5.5.4 you’re good to go. If it’s 4.x.x You’re sill running the old version and need to redo the suggestion above.

If you click on the new icon and nothing happens just re-edit the entry and make sure the command is just systemsettings5 with none of the old switches/options that were present in the 4.x.x version.