Bug 365461

That frankly looks like a bug in the specific theme. The top elements seem invalid and the lower right section is junk as well.
I'd contact the author of the theme to have him seek to fix it.

could you please attach a screenshot? Also please provide the output of:
qdbus org.kde.KWin /KWin supportInformation

The (not so great) screenshot is linked as url

I try others themes and i have the same problem, only the default theme works fine.

The output the command is:

Version
=======
KWin version: 5.7.0
Qt Version: 5.7.0
Qt compile version: 5.7.0
XCB compile version: 1.12

Operation Mode: X11 only

Build Options
=============
KWIN_BUILD_DECORATIONS: yes
KWIN_BUILD_TABBOX: yes
KWIN_BUILD_ACTIVITIES: yes
HAVE_INPUT: yes
HAVE_DRM: yes
HAVE_GBM: yes
HAVE_X11_XCB: yes
HAVE_EPOXY_GLX: yes
HAVE_WAYLAND_EGL: yes

X11
===
Vendor: The X.Org Foundation
Vendor Release: 11803000
Protocol Version/Revision: 11/0
SHAPE: yes; Version: 0x11
RANDR: yes; Version: 0x14
DAMAGE: yes; Version: 0x11
Composite: yes; Version: 0x4
RENDER: yes; Version: 0xb                                                                                                                                                          
XFIXES: yes; Version: 0x50                                                                                                                                                         
SYNC: yes; Version: 0x31                                                                                                                                                           
GLX: yes; Version: 0x0                                                                                                                                                             
                                                                                                                                                                                   
Decoration                                                                                                                                                                         
==========                                                                                                                                                                         
Plugin: org.kde.kwin.aurorae                                                                                                                                                       
Theme: __aurorae__svg__Yosemite                                                                                                                                                    
Blur: 1                                                                                                                                                                            
onAllDesktopsAvailable: true
alphaChannelSupported: true
closeOnDoubleClickOnMenu: false
decorationButtonsLeft: 0, 2
decorationButtonsRight: 6, 3, 4, 5
borderSize: 3
gridUnit: 10
font: Noto Sans,10,-1,0,50,0,0,0,0,0
smallSpacing: 2
largeSpacing: 10

Options
=======
focusPolicy: 0
nextFocusPrefersMouse: false
clickRaise: true
autoRaise: false
autoRaiseInterval: 0
delayFocusInterval: 0
shadeHover: false
shadeHoverInterval: 250
separateScreenFocus: false
placement: 4
focusPolicyIsReasonable: true
borderSnapZone: 10
windowSnapZone: 10
centerSnapZone: 0
snapOnlyWhenOverlapping: false
rollOverDesktops: true
focusStealingPreventionLevel: 1
legacyFullscreenSupport: false
operationTitlebarDblClick: 5000
operationMaxButtonLeftClick: 5000
operationMaxButtonMiddleClick: 5015
operationMaxButtonRightClick: 5014
commandActiveTitlebar1: 0
commandActiveTitlebar2: 30
commandActiveTitlebar3: 2
commandInactiveTitlebar1: 4
commandInactiveTitlebar2: 30
commandInactiveTitlebar3: 2
commandWindow1: 7
commandWindow2: 8
commandWindow3: 8
commandWindowWheel: 31
commandAll1: 10
commandAll2: 3
commandAll3: 14
keyCmdAllModKey: 16777251
showGeometryTip: false
condensedTitle: false
electricBorderMaximize: true
electricBorderTiling: true
electricBorderCornerRatio: 0.25
borderlessMaximizedWindows: false
killPingTimeout: 5000
hideUtilityWindowsForInactive: true
inactiveTabsSkipTaskbar: false
autogroupSimilarWindows: false
autogroupInForeground: true
compositingMode: 1
useCompositing: true
compositingInitialized: true
hiddenPreviews: 1
unredirectFullscreen: false
glSmoothScale: 1
colorCorrected: false
xrenderSmoothScale: false
maxFpsInterval: 16666666
refreshRate: 0
vBlankTime: 6000000
glStrictBinding: false
glStrictBindingFollowsDriver: true
glCoreProfile: false
glPreferBufferSwap: 0
glPlatformInterface: 1

Screen Edges
============
desktopSwitching: false
desktopSwitchingMovingClients: false
cursorPushBackDistance: 1x1
timeThreshold: 150
reActivateThreshold: 350
actionTopLeft: 0
actionTop: 0
actionTopRight: 0
actionRight: 0
actionBottomRight: 0
actionBottom: 0
actionBottomLeft: 0
actionLeft: 0

Screens
=======
Multi-Head: no
Active screen follows mouse:  no
Number of Screens: 1

Screen 0:
---------
Name: HDMI-0
Geometry: 0,0,1920x1080
Refresh Rate: 60


Compositing
===========
Compositing is active
Compositing Type: OpenGL
OpenGL vendor string: NVIDIA Corporation
OpenGL renderer string: GeForce GTX 660/PCIe/SSE2
OpenGL version string: 4.5.0 NVIDIA 367.27
OpenGL platform interface: GLX
OpenGL shading language version string: 4.50 NVIDIA
Driver: NVIDIA
Driver version: 367.27
GPU class: Unknown
OpenGL version: 4.5
GLSL version: 4.50
X server version: 1.18.3
Linux kernel version: 4.6.3
Direct rendering: Requires strict binding: no
GLSL shaders:  yes
Texture NPOT support:  yes
Virtual Machine:  no
OpenGL 2 Shaders are used
Painting blocks for vertical retrace:  no

Loaded Effects:
---------------
zoom
slidingpopups
kwin4_effect_login
kwin4_effect_scalein
screenshot
kwin4_effect_windowaperture
magiclamp
kwin4_effect_translucency
desktopgrid
cubeslide
sheet
kwin4_effect_maximize
kwin4_effect_morphingpopups
kwin4_effect_fade
kwin4_effect_dialogparent
presentwindows
highlightwindow
logout
startupfeedback
screenedge
kscreen

Currently Active Effects:
-------------------------

Effect Settings:
----------------
zoom:
zoomFactor: 1.2
mousePointer: 0
mouseTracking: 0
enableFocusTracking: false
followFocus: true
focusDelay: 350
moveFactor: 20
targetZoom: 1

slidingpopups:
fadeInTime: 150
fadeOutTime: 250

kwin4_effect_login:

kwin4_effect_scalein:

screenshot:

kwin4_effect_windowaperture:

magiclamp:
animationDuration: 250

kwin4_effect_translucency:

desktopgrid:
zoomDuration: 300
border: 10
desktopNameAlignment: 0
layoutMode: 0
customLayoutRows: 2
usePresentWindows: true

cubeslide:
rotationDuration: 500
dontSlidePanels: true
dontSlideStickyWindows: false
usePagerLayout: true
useWindowMoving: false

sheet:
duration: 500

kwin4_effect_maximize:

kwin4_effect_morphingpopups:

kwin4_effect_fade:

kwin4_effect_dialogparent:

presentwindows:
layoutMode: 0
showCaptions: true
showIcons: true
doNotCloseWindows: false
ignoreMinimized: false
accuracy: 20
fillGaps: true
fadeDuration: 150
showPanel: false
leftButtonWindow: 1
rightButtonWindow: 2
middleButtonWindow: 0
leftButtonDesktop: 2
middleButtonDesktop: 0
rightButtonDesktop: 0

highlightwindow:

logout:
useBlur: true

startupfeedback:
type: 1

screenedge:

kscreen:

I try with more themes and works fine, it happened that several issues had a similar problem. Sorry for the inconvenience.