Bug 1304263

What menu/widget are you talking about? 

kscreen doesn't provide any .desktop file to display in application menus (like kickoff), those typically are under /usr/share/applications/...

 you mean in systemsettings ?  systemsettings5 ->  display&monitor -> display configuration ?

I received the error message "Unable to run the command specified. The file or folder kcm_kscreen.desktop does not exist." when I try to launch the "Display configuration" from Favorites in Kmenu or if I launch it from panel after "Add to panel" action.
Moreover if I access it by systemsetting the tool is not able to detect new monitor attached both to VGA port and hdmi port.

I add system info:

[root@localhost ~]# cat /etc/fedora-release 
Fedora release 23 (Twenty Three)
[root@localhost ~]# uname -a
Linux localhost.localdomain 4.3.5-300.fc23.x86_64 #1 SMP Mon Feb 1 03:18:41 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
[root@localhost ~]# 


[root@localhost ~]# rpm -qa | grep kcm                                                                                                                            
kf5-kcmutils-5.18.0-1.fc23.x86_64
ktp-accounts-kcm-15.12.1-1.fc23.x86_64
sddm-kcm-5.5.4-1.fc23.x86_64
kcm-gtk-0.5.3-18.fc23.x86_64
kcm_systemd-1.2.1-1.fc23.x86_64
kcm_colors-4.11.22-2.fc23.x86_64
[root@localhost ~]#

I guess I'm curious how this ended up in your favorites (or panel) to begin with, this package does not normally appear in kickoff application menu (only systemsettings).

Probably better to focus on the latter issue you mentioned: 
Moreover if I access it by systemsetting the tool is not able to detect new monitor attached both to VGA port and hdmi port.

Try running this from konsole:
xrandr


Do your newly attached monitors appear listed there?

from the kmenu I searched (texting) "display" an it appears.

I run the xrandr, this is the output, but the "Display configuration" do NOT displays the VGA one.

[root@localhost ~]# xrandr 
Screen 0: minimum 8 x 8, current 1366 x 768, maximum 32767 x 32767
LVDS1 connected primary 1366x768+0+0 (normal left inverted right x axis y axis) 277mm x 156mm
   1366x768      60.02*+
   1280x720      60.00  
   1024x768      60.00  
   1024x576      60.00  
   960x540       60.00  
   800x600       60.32    56.25  
   864x486       60.00  
   640x480       59.94  
   720x405       60.00  
   680x384       60.00  
   640x360       60.00  
DP1 disconnected (normal left inverted right x axis y axis)
DP2 disconnected (normal left inverted right x axis y axis)
DP3 disconnected (normal left inverted right x axis y axis)
HDMI1 disconnected (normal left inverted right x axis y axis)
HDMI2 disconnected (normal left inverted right x axis y axis)
HDMI3 disconnected (normal left inverted right x axis y axis)
VGA1 connected (normal left inverted right x axis y axis)
   1920x1080     60.00 +
   1600x1200     60.00  
   1680x1050     59.95  
   1280x1024     75.02    70.00    60.02  
   1440x900      59.89  
   1280x960      60.00  
   1152x864      75.00  
   1024x768      75.08    70.07    60.00  
   832x624       74.55  
   800x600       75.00    60.32    56.25  
   640x480       75.00    72.81    60.00  
VIRTUAL1 disconnected (normal left inverted right x axis y axis)
[root@localhost ~]#

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