In the actualization, the desktop is in black & white, no image, plasma close requently.
this is the report:
Application: plasmashell (5.5.5)

Qt Version: 5.5.1
Operating System: Linux 4.4.0-34-generic x86_64
Distribution: Ubuntu 16.04.1 LTS

-- Information about the crash:
<En detalle, comente que estaba haciendo cuando la aplicación se cerró.>

-- Backtrace:
Application: Plasma (plasmashell), signal: Aborted
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7fb0759c38c0 (LWP 2941))]

Thread 8 (Thread 0x7fafb1c00700 (LWP 3125)):
#0  0x00007fb06ceb3ac9 in g_mutex_lock () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#1  0x00007fb06ce6ef26 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fb06ce6f400 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007fb06ce6f4ac in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007fb070a06a9b in QEventDispatcherGlib::processEvents (this=0x7fafac0008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x00007fb0709addea in QEventLoop::exec (this=this@entry=0x7fafb1bffcc0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007fb0707ca8a4 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:503
#7  0x00007fafb40df7d7 in KCupsConnection::run() () from /usr/lib/x86_64-linux-gnu/libkcupslib.so
#8  0x00007fb0707cf84e in QThreadPrivate::start (arg=0x2797ab0) at thread/qthread_unix.cpp:331
#9  0x00007fb06f8bc6fa in start_thread (arg=0x7fafb1c00700) at pthread_create.c:333
#10 0x00007fb0700e5b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 7 (Thread 0x7fb040aa3700 (LWP 3001)):
#0  0x00007fb06ce6c3e7 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#1  0x00007fb06ce6e8cb in g_main_context_prepare () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fb06ce6f2cb in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007fb06ce6f4ac in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007fb070a06a9b in QEventDispatcherGlib::processEvents (this=0x7fafb80008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x00007fb0709addea in QEventLoop::exec (this=this@entry=0x7fb040aa2c90, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007fb0707ca8a4 in QThread::exec (this=this@entry=0x24efb80) at thread/qthread.cpp:503
#7  0x00007fb0739f8ed6 in QQuickPixmapReader::run (this=0x24efb80) at util/qquickpixmapcache.cpp:817
#8  0x00007fb0707cf84e in QThreadPrivate::start (arg=0x24efb80) at thread/qthread_unix.cpp:331
#9  0x00007fb06f8bc6fa in start_thread (arg=0x7fb040aa3700) at pthread_create.c:333
#10 0x00007fb0700e5b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 6 (Thread 0x7fb0433ef700 (LWP 2993)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007fb075417bd4 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#2  0x00007fb075417c19 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#3  0x00007fb06f8bc6fa in start_thread (arg=0x7fb0433ef700) at pthread_create.c:333
#4  0x00007fb0700e5b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 5 (Thread 0x7fb048e1b700 (LWP 2975)):
#0  0x00007fb06ceb3ae4 in g_mutex_unlock () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#1  0x00007fb06ce6edc9 in g_main_context_check () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fb06ce6f340 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007fb06ce6f4ac in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007fb070a06a9b in QEventDispatcherGlib::processEvents (this=0x7fb03c0008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x00007fb0709addea in QEventLoop::exec (this=this@entry=0x7fb048e1ace0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007fb0707ca8a4 in QThread::exec (this=this@entry=0x23fa1a0) at thread/qthread.cpp:503
#7  0x00007fb0730723c5 in QQmlThreadPrivate::run (this=0x23fa1a0) at qml/ftw/qqmlthread.cpp:141
#8  0x00007fb0707cf84e in QThreadPrivate::start (arg=0x23fa1a0) at thread/qthread_unix.cpp:331
#9  0x00007fb06f8bc6fa in start_thread (arg=0x7fb048e1b700) at pthread_create.c:333
#10 0x00007fb0700e5b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 4 (Thread 0x7fb04acf9700 (LWP 2969)):
#0  0x00007fb0707c79aa in QBasicAtomicOps<8>::testAndSetRelaxed<QMutexData*> (currentValue=<synthetic pointer>, newValue=0x1, expectedValue=0x0, _q_value=@0x23260a8: 0x1) at ../../include/QtCore/../../src/corelib/arch/qatomic_x86.h:259
#1  QGenericAtomicOps<QBasicAtomicOps<8> >::testAndSetAcquire<QMutexData*, QMutexData*> (currentValue=<synthetic pointer>, newValue=<optimized out>, expectedValue=0x0, _q_value=@0x23260a8: 0x1) at ../../include/QtCore/../../src/corelib/thread/qgenericatomic.h:166
#2  QBasicAtomicPointer<QMutexData>::testAndSetAcquire (currentValue=<synthetic pointer>, newValue=<optimized out>, expectedValue=0x0, this=0x23260a8, this@entry=0x29) at ../../include/QtCore/../../src/corelib/thread/qbasicatomic.h:276
#3  QBasicMutex::fastTryLock (current=<synthetic pointer>, this=0x23260a8, this@entry=0x29) at thread/qmutex.h:82
#4  QMutex::lock (this=this@entry=0x23260a8) at thread/qmutex.cpp:212
#5  0x00007fb070a062f9 in QMutexLocker::QMutexLocker (m=0x23260a8, this=<synthetic pointer>) at ../../include/QtCore/../../src/corelib/thread/qmutex.h:128
#6  QThreadData::canWaitLocked (this=0x2326080) at ../../include/QtCore/5.5.1/QtCore/private/../../../../../src/corelib/thread/qthread_p.h:240
#7  postEventSourcePrepare (timeout=<synthetic pointer>, s=0x7fb0440012d0) at kernel/qeventdispatcher_glib.cpp:254
#8  postEventSourceCheck (source=0x7fb0440012d0) at kernel/qeventdispatcher_glib.cpp:264
#9  0x00007fb06ce6edd1 in g_main_context_check () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#10 0x00007fb06ce6f340 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#11 0x00007fb06ce6f4ac in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#12 0x00007fb070a06a9b in QEventDispatcherGlib::processEvents (this=0x7fb0440008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#13 0x00007fb0709addea in QEventLoop::exec (this=this@entry=0x7fb04acf8ce0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#14 0x00007fb0707ca8a4 in QThread::exec (this=this@entry=0x2325b10) at thread/qthread.cpp:503
#15 0x00007fb0730723c5 in QQmlThreadPrivate::run (this=0x2325b10) at qml/ftw/qqmlthread.cpp:141
#16 0x00007fb0707cf84e in QThreadPrivate::start (arg=0x2325b10) at thread/qthread_unix.cpp:331
#17 0x00007fb06f8bc6fa in start_thread (arg=0x7fb04acf9700) at pthread_create.c:333
#18 0x00007fb0700e5b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 3 (Thread 0x7fb05a1fc700 (LWP 2952)):
#0  0x00007fb06ceb3ae4 in g_mutex_unlock () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#1  0x00007fb06ce6f24d in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fb06ce6f4ac in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007fb070a06a9b in QEventDispatcherGlib::processEvents (this=0x7fb0540008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#4  0x00007fb0709addea in QEventLoop::exec (this=this@entry=0x7fb05a1fbce0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#5  0x00007fb0707ca8a4 in QThread::exec (this=this@entry=0x208d9c0) at thread/qthread.cpp:503
#6  0x00007fb0730723c5 in QQmlThreadPrivate::run (this=0x208d9c0) at qml/ftw/qqmlthread.cpp:141
#7  0x00007fb0707cf84e in QThreadPrivate::start (arg=0x208d9c0) at thread/qthread_unix.cpp:331
#8  0x00007fb06f8bc6fa in start_thread (arg=0x7fb05a1fc700) at pthread_create.c:333
#9  0x00007fb0700e5b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7fb060a70700 (LWP 2945)):
#0  0x00007fb0700d9e8d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007fb07419ec62 in ?? () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#2  0x00007fb0741a08d7 in xcb_wait_for_event () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#3  0x00007fb062bbe629 in QXcbEventReader::run (this=0x1faca30) at qxcbconnection.cpp:1253
#4  0x00007fb0707cf84e in QThreadPrivate::start (arg=0x1faca30) at thread/qthread_unix.cpp:331
#5  0x00007fb06f8bc6fa in start_thread (arg=0x7fb060a70700) at pthread_create.c:333
#6  0x00007fb0700e5b5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7fb0759c38c0 (LWP 2941)):
[KCrash Handler]
#6  0x00007fb070014418 in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:54
#7  0x00007fb07001601a in __GI_abort () at abort.c:89
#8  0x00007fb07000cbd7 in __assert_fail_base (fmt=<optimized out>, assertion=assertion@entry=0x7fb052eb6728 "bkref", file=file@entry=0x7fb052eb670a "../../nouveau/pushbuf.c", line=line@entry=238, function=function@entry=0x7fb052eb6768 <__PRETTY_FUNCTION__.6215> "pushbuf_krel") at assert.c:92
#9  0x00007fb07000cc82 in __GI___assert_fail (assertion=assertion@entry=0x7fb052eb6728 "bkref", file=file@entry=0x7fb052eb670a "../../nouveau/pushbuf.c", line=line@entry=238, function=function@entry=0x7fb052eb6768 <__PRETTY_FUNCTION__.6215> "pushbuf_krel") at assert.c:101
#10 0x00007fb052eb44ac in pushbuf_krel (push=push@entry=0x21dd6b0, bo=<optimized out>, data=<optimized out>, flags=<optimized out>, vor=<optimized out>, tor=<optimized out>) at ../../nouveau/pushbuf.c:238
#11 0x00007fb052eb5952 in nouveau_pushbuf_reloc (push=0x21dd6b0, bo=<optimized out>, data=<optimized out>, flags=<optimized out>, vor=<optimized out>, tor=<optimized out>) at ../../nouveau/pushbuf.c:746
#12 0x00007fb05351fb70 in ?? () from /usr/lib/x86_64-linux-gnu/dri/nouveau_dri.so
#13 0x00007fb053509e8c in ?? () from /usr/lib/x86_64-linux-gnu/dri/nouveau_dri.so
#14 0x00007fb05350a048 in ?? () from /usr/lib/x86_64-linux-gnu/dri/nouveau_dri.so
#15 0x00007fb05347fbd6 in ?? () from /usr/lib/x86_64-linux-gnu/dri/nouveau_dri.so
#16 0x00007fb0532b2766 in ?? () from /usr/lib/x86_64-linux-gnu/dri/nouveau_dri.so
#17 0x00007fb0531715c7 in ?? () from /usr/lib/x86_64-linux-gnu/dri/nouveau_dri.so
#18 0x00007fb05317192f in ?? () from /usr/lib/x86_64-linux-gnu/dri/nouveau_dri.so
#19 0x00007fb073a219df in QOpenGLFunctions::glBufferData (usage=<optimized out>, data=<optimized out>, size=<optimized out>, target=34962, this=0x3cbd268) at /usr/include/x86_64-linux-gnu/qt5/QtGui/qopenglfunctions.h:1185
#20 QSGBatchRenderer::Renderer::unmap (this=this@entry=0x3cbd190, buffer=buffer@entry=0x44dc938, isIndexBuf=isIndexBuf@entry=false) at scenegraph/coreapi/qsgbatchrenderer.cpp:911
#21 0x00007fb073a23db9 in QSGBatchRenderer::Renderer::uploadBatch (this=this@entry=0x3cbd190, b=b@entry=0x44dc910) at scenegraph/coreapi/qsgbatchrenderer.cpp:1979
#22 0x00007fb073a2ee46 in QSGBatchRenderer::Renderer::render (this=<optimized out>) at scenegraph/coreapi/qsgbatchrenderer.cpp:2667
#23 0x00007fb073a3ab6f in QSGRenderer::renderScene (this=0x3cbd190, bindable=...) at scenegraph/coreapi/qsgrenderer.cpp:208
#24 0x00007fb073a3b3bb in QSGRenderer::renderScene (this=<optimized out>, fboId=<optimized out>) at scenegraph/coreapi/qsgrenderer.cpp:168
#25 0x00007fb073a4b87e in QSGRenderContext::renderNextFrame (this=0x21c3c50, renderer=0x3cbd190, fboId=<optimized out>) at scenegraph/qsgcontext.cpp:558
#26 0x00007fb073a960db in QQuickWindowPrivate::renderSceneGraph (this=this@entry=0x29eb420, size=...) at items/qquickwindow.cpp:383
#27 0x00007fb073a6619b in QSGGuiThreadRenderLoop::renderWindow (this=this@entry=0x21f3030, window=0x29e8260) at scenegraph/qsgrenderloop.cpp:378
#28 0x00007fb073a672a1 in QSGGuiThreadRenderLoop::event (this=0x21f3030, e=<optimized out>) at scenegraph/qsgrenderloop.cpp:474
#29 0x00007fb0714b305c in QApplicationPrivate::notify_helper (this=this@entry=0x1f94890, receiver=receiver@entry=0x21f3030, e=e@entry=0x7fffc390a880) at kernel/qapplication.cpp:3716
#30 0x00007fb0714b8516 in QApplication::notify (this=0x7fffc390ac20, receiver=0x21f3030, e=0x7fffc390a880) at kernel/qapplication.cpp:3499
#31 0x00007fb0709b062b in QCoreApplication::notifyInternal (this=0x7fffc390ac20, receiver=0x21f3030, event=event@entry=0x7fffc390a880) at kernel/qcoreapplication.cpp:965
#32 0x00007fb070a0589d in QCoreApplication::sendEvent (event=0x7fffc390a880, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:224
#33 QTimerInfoList::activateTimers (this=0x1fd8bd0) at kernel/qtimerinfo_unix.cpp:637
#34 0x00007fb070a05da1 in timerSourceDispatch (source=<optimized out>) at kernel/qeventdispatcher_glib.cpp:177
#35 0x00007fb06ce6f1a7 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#36 0x00007fb06ce6f400 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#37 0x00007fb06ce6f4ac in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#38 0x00007fb070a06a7f in QEventDispatcherGlib::processEvents (this=0x1fccb80, flags=...) at kernel/qeventdispatcher_glib.cpp:418
#39 0x00007fb0709addea in QEventLoop::exec (this=this@entry=0x7fffc390aac0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#40 0x00007fb0709b5e8c in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1229
#41 0x00007fb070ce9c3c in QGuiApplication::exec () at kernel/qguiapplication.cpp:1542
#42 0x00007fb0714af495 in QApplication::exec () at kernel/qapplication.cpp:2976
#43 0x0000000000432d4a in main (argc=2, argv=<optimized out>) at /build/plasma-workspace-kxRFE_/plasma-workspace-5.5.5.2/shell/main.cpp:181


Reproducible: Always

Steps to Reproduce:
1.When Kubuntu start
2.Desktop preferences
3.