Created attachment 96801 [details]
My desktop looks like this

Since last time I had about 50 other crash . 10 percent of them were total crash without automatic recovery.
I made observation of the phenomena .
For instance one crash happened while sweeping the mouse index from a .odt file to the next one a jpg file. When the mouse pointer is above a icon , the icon expand to make a preview.
Another crash : I wanted to push a file in a folder in order to copy  it. I took the mouse pointer over the file then click left on the mouse (in order to dragg it) . At that moment I had a crash with automatic recovery. Few minutes after i did the same : no crash !

Here one of the last debug infos
Application: Outil de gestion de fenêtres Plasma (plasma-desktop), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f7b65f7d780 (LWP 3370))]

Thread 3 (Thread 0x7f7b3a345700 (LWP 3371)):
#0  0x00007f7b6480c67f in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1  0x00007f7b56d3f73a in QTWTF::TCMalloc_PageHeap::scavengerThread() () from /lib64/libQtScript.so.4
#2  0x00007f7b56d3f769 in QTWTF::TCMalloc_PageHeap::runScavengerThread(void*) () from /lib64/libQtScript.so.4
#3  0x00007f7b648075bd in start_thread () from /lib64/libpthread.so.0
#4  0x00007f7b635805cd in clone () from /lib64/libc.so.6

Thread 2 (Thread 0x7f7ab2c98700 (LWP 3377)):
#0  0x00007f7b6358dc2f in __libc_enable_asynccancel () from /lib64/libc.so.6
#1  0x00007f7b63574d12 in poll () from /lib64/libc.so.6
#2  0x00007f7b6065aeb4 in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0
#3  0x00007f7b6065afbc in g_main_context_iteration () from /lib64/libglib-2.0.so.0
#4  0x00007f7b64bc4e3e in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQtCore.so.4
#5  0x00007f7b64b96931 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQtCore.so.4
#6  0x00007f7b64b96c45 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQtCore.so.4
#7  0x00007f7b64a94899 in QThread::exec() () from /lib64/libQtCore.so.4
#8  0x00007f7b64b783d3 in QInotifyFileSystemWatcherEngine::run() () from /lib64/libQtCore.so.4
#9  0x00007f7b64a96fff in QThreadPrivate::start(void*) () from /lib64/libQtCore.so.4
#10 0x00007f7b648075bd in start_thread () from /lib64/libpthread.so.0
#11 0x00007f7b635805cd in clone () from /lib64/libc.so.6

Thread 1 (Thread 0x7f7b65f7d780 (LWP 3370)):
[KCrash Handler]
#5  0x00007f7aa2b31fb1 in mov_probe () from /lib64/libavformat.so.56
#6  0x00007f7aa81dd6a5 in FFMPEGEndAnalyzer::analyze(Strigi::AnalysisResult&, Strigi::StreamBase<char>*) () from /usr/lib64/strigi/strigiea_ffmpeg.so
#7  0x00007f7b5ade96a8 in Strigi::StreamAnalyzerPrivate::analyze(Strigi::AnalysisResult&, Strigi::StreamBase<char>*) () from /lib64/libstreamanalyzer.so.0
#8  0x00007f7b5adc0bf5 in Strigi::AnalysisResult::indexChild(std::string const&, long, Strigi::StreamBase<char>*) () from /lib64/libstreamanalyzer.so.0
#9  0x00007f7b5ae04753 in OdfEndAnalyzer::analyze(Strigi::AnalysisResult&, Strigi::StreamBase<char>*) () from /lib64/libstreamanalyzer.so.0
#10 0x00007f7b5ade96a8 in Strigi::StreamAnalyzerPrivate::analyze(Strigi::AnalysisResult&, Strigi::StreamBase<char>*) () from /lib64/libstreamanalyzer.so.0
#11 0x00007f7b5b451471 in KFileMetaInfoPrivate::init(QIODevice&, KUrl const&, long, QFlags<KFileMetaInfo::What>) () from /usr/lib64/libkio.so.5
#12 0x00007f7b5b45195a in KFileMetaInfo::KFileMetaInfo(QString const&, QString const&, QFlags<KFileMetaInfo::What>) () from /usr/lib64/libkio.so.5
#13 0x00007f7b5b43e95f in KFileItem::metaInfo(bool, int) const () from /usr/lib64/libkio.so.5
#14 0x00007f7b428bdf6c in ToolTipWidget::metaInfo() const () from /usr/lib64/kde4/plasma_applet_folderview.so
#15 0x00007f7b428c07fb in ToolTipWidget::setContent() () from /usr/lib64/kde4/plasma_applet_folderview.so
#16 0x00007f7b428c0aee in ToolTipWidget::toolTipAboutToShow() () from /usr/lib64/kde4/plasma_applet_folderview.so
#17 0x00007f7b64b9fa72 in QMetaMethod::invoke(QObject*, Qt::ConnectionType, QGenericReturnArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument) const () from /lib64/libQtCore.so.4
#18 0x00007f7b64ba1d2e in QMetaObject::invokeMethod(QObject*, char const*, Qt::ConnectionType, QGenericReturnArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument, QGenericArgument) () from /lib64/libQtCore.so.4
#19 0x00007f7b5970869a in Plasma::ToolTipManagerPrivate::showToolTip() () from /usr/lib64/libplasma.so.3
#20 0x00007f7b59709069 in Plasma::ToolTipManager::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) [clone .part.25] () from /usr/lib64/libplasma.so.3
#21 0x00007f7b64bab88a in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /lib64/libQtCore.so.4
#22 0x00007f7b64bafc2b in QObject::event(QEvent*) () from /lib64/libQtCore.so.4
#23 0x00007f7b63d0f79c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /lib64/libQtGui.so.4
#24 0x00007f7b63d15e40 in QApplication::notify(QObject*, QEvent*) () from /lib64/libQtGui.so.4
#25 0x00007f7b6595d25a in KApplication::notify(QObject*, QEvent*) () from /lib64/libkdeui.so.5
#26 0x00007f7b64b97cad in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /lib64/libQtCore.so.4
#27 0x00007f7b64bc731b in QTimerInfoList::activateTimers() () from /lib64/libQtCore.so.4
#28 0x00007f7b64bc44f9 in idleTimerSourceDispatch(_GSource*, int (*)(void*), void*) () from /lib64/libQtCore.so.4
#29 0x00007f7b6065ac6d in g_main_context_dispatch () from /lib64/libglib-2.0.so.0
#30 0x00007f7b6065af18 in g_main_context_iterate.isra () from /lib64/libglib-2.0.so.0
#31 0x00007f7b6065afbc in g_main_context_iteration () from /lib64/libglib-2.0.so.0
#32 0x00007f7b64bc4e1e in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQtCore.so.4
#33 0x00007f7b63dad4f6 in QGuiEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQtGui.so.4
#34 0x00007f7b64b96931 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQtCore.so.4
#35 0x00007f7b64b96c45 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQtCore.so.4
#36 0x00007f7b64b9be59 in QCoreApplication::exec() () from /lib64/libQtCore.so.4
#37 0x00007f7b4e0f936d in kdemain () from /usr/lib64/libkdeinit4_plasma-desktop.so
#38 0x000000000040819a in launch(int, char const*, char const*, char const*, int, char const*, bool, char const*, bool, char const*) ()
#39 0x0000000000409021 in handle_launcher_request(int, char const*) [clone .isra.15] ()
#40 0x000000000040972a in handle_requests(int) ()
#41 0x0000000000405303 in main ()

Hello!

This bug report was filed for KDE Plasma 4, which reached end-of-support status in August 2015. KDE Plasma 5's desktop shell has been almost completely rewritten for better performance and usability, so it is likely that this bug has already been resolved in Plasma 5.

Accordingly, we hope you understand why we must close this bug report. If the issue described  here is still present in KDE Plasma 5.12 or later, please feel free to open a new ticket in the "plasmashell" product after reading https://community.kde.org/Get_Involved/Bug_Reporting

If you would like to get involved in KDE's bug triaging effort so that future mass bug closes like this are less likely, please read https://community.kde.org/Get_Involved#Bug_Triaging

Thanks for your understanding!

Nate Graham