Drkonqi failed to submit the crash, probably due to proxy issues. I went through each of the possible duplicates and found no matches.

Here is the contents of the report that it assembled including my description:

Application: kwin (4.11.11)
KDE Platform Version: 4.13.3
Qt Version: 4.8.6
Operating System: Linux 3.13.0-46-generic x86_64
Distribution: Ubuntu 14.04.2 LTS

-- Information about the crash:
- What I was doing when the application crashed:

I was running Eclipse on a remote node and displaying it via NoMachine's NX in "floating window" mode. This is the first and only time this has happened (so far). The Eclipse session kept running without problem and there was no disruption to my NX session. It was just the window manager itself. My window decorations disappeared and my backdrops were replaced by the default. When I accepted KDE's offer to restart, it worked and the window decorations re-appeared with one notable exception: a LibreOffice Impress window (4.4.1.2 installed in /opt yesterday). XTerms (local and remote), Thunderbird, Firefox, PIdgin all had their window decorations restored.

The platform is a corporate Ubuntu 14.04 installation running on a Dell ZBook15. It is normally a very stable system.

-- Backtrace:
Application: KWin (kwin), signal: Aborted
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7fe36bbaf800 (LWP 4167))]

Thread 3 (Thread 0x7fe33f5ff700 (LWP 4197)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007fe36a575ffb in ?? () from /usr/lib/x86_64-linux-gnu/libQtScript.so.4
#2  0x00007fe36a576039 in ?? () from /usr/lib/x86_64-linux-gnu/libQtScript.so.4
#3  0x00007fe36311a182 in start_thread (arg=0x7fe33f5ff700) at pthread_create.c:312
#4  0x00007fe36b38647d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 2 (Thread 0x7fe34d56c700 (LWP 25840)):
#0  0x00007fe36b37dda3 in select () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007fe36576f2c7 in qt_safe_select (nfds=13, fdread=0x7fe348006608, fdwrite=0x7fe3480068a0, fdexcept=0x7fe348006b38, orig_timeout=0x0) at kernel/qcore_unix.cpp:79
#2  0x00007fe365774824 in QEventDispatcherUNIXPrivate::doSelect (this=this@entry=0x7fe348006450, flags=..., timeout=0x0) at kernel/qeventdispatcher_unix.cpp:223
#3  0x00007fe365774c92 in QEventDispatcherUNIX::processEvents (this=0x7fe3480008f0, flags=...) at kernel/qeventdispatcher_unix.cpp:936
#4  0x00007fe3657430af in QEventLoop::processEvents (this=this@entry=0x7fe34d56bda0, flags=...) at kernel/qeventloop.cpp:149
#5  0x00007fe3657433a5 in QEventLoop::exec (this=this@entry=0x7fe34d56bda0, flags=...) at kernel/qeventloop.cpp:204
#6  0x00007fe36563fc5f in QThread::exec (this=this@entry=0x2df2cc0) at thread/qthread.cpp:537
#7  0x00007fe365724823 in QInotifyFileSystemWatcherEngine::run (this=0x2df2cc0) at io/qfilesystemwatcher_inotify.cpp:265
#8  0x00007fe36564232f in QThreadPrivate::start (arg=0x2df2cc0) at thread/qthread_unix.cpp:349
#9  0x00007fe36311a182 in start_thread (arg=0x7fe34d56c700) at pthread_create.c:312
#10 0x00007fe36b38647d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

Thread 1 (Thread 0x7fe36bbaf800 (LWP 4167)):
[KCrash Handler]
#6  0x00007fe36b2c2cc9 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
#7  0x00007fe36b2c60d8 in __GI_abort () at abort.c:89
#8  0x00007fe36b2ff394 in __libc_message (do_abort=do_abort@entry=1, fmt=fmt@entry=0x7fe36b40db28 "*** Error in `%s': %s: 0x%s ***\n") at ../sysdeps/posix/libc_fatal.c:175
#9  0x00007fe36b30b66e in malloc_printerr (ptr=<optimized out>, str=0x7fe36b40dcc8 "free(): invalid next size (fast)", action=1) at malloc.c:4996
#10 _int_free (av=<optimized out>, p=<optimized out>, have_lock=0) at malloc.c:3840
#11 0x00007fe36b719336 in ~Phase2Data (this=0x2b04a78, __in_chrg=<optimized out>) at ../../kwin/scene.h:143
#12 ~QPair (this=0x2b04a70, __in_chrg=<optimized out>) at /usr/include/qt4/QtCore/qpair.h:54
#13 node_destruct (this=<optimized out>, to=0x31a0038, from=0x319fff8) at /usr/include/qt4/QtCore/qlist.h:431
#14 QList<QPair<KWin::Scene::Window*, KWin::Scene::Phase2Data> >::free (data=0x319ffe0, this=<optimized out>) at /usr/include/qt4/QtCore/qlist.h:757
#15 0x00007fe36b71aafa in ~QList (this=0x7fff0f7231f0, __in_chrg=<optimized out>) at /usr/include/qt4/QtCore/qlist.h:732
#16 KWin::Scene::paintSimpleScreen (this=this@entry=0x212e380, orig_mask=orig_mask@entry=8, region=...) at ../../kwin/scene.cpp:394
#17 0x00007fe36b7189b5 in KWin::Scene::finalPaintScreen (this=0x212e380, mask=mask@entry=8, region=..., data=...) at ../../kwin/scene.cpp:198
#18 0x00007fe36b73ae1d in KWin::EffectsHandlerImpl::paintScreen (this=0x26778e0, mask=mask@entry=8, region=..., data=...) at ../../kwin/effects.cpp:375
#19 0x00007fe36ae50d5f in KWin::Effect::paintScreen (this=this@entry=0x236c060, mask=mask@entry=8, region=..., data=...) at ../../../kwin/libkwineffects/kwineffects.cpp:522
#20 0x00007fe36b73adda in KWin::EffectsHandlerImpl::paintScreen (this=0x26778e0, mask=mask@entry=8, region=..., data=...) at ../../kwin/effects.cpp:372
#21 0x00007fe36ae50d5f in KWin::Effect::paintScreen (this=this@entry=0x21db000, mask=mask@entry=8, region=..., data=...) at ../../../kwin/libkwineffects/kwineffects.cpp:522
#22 0x00007fe36b73adda in KWin::EffectsHandlerImpl::paintScreen (this=0x26778e0, mask=mask@entry=8, region=..., data=...) at ../../kwin/effects.cpp:372
#23 0x00007fe36ae50d5f in KWin::Effect::paintScreen (this=this@entry=0x20eb410, mask=mask@entry=8, region=..., data=...) at ../../../kwin/libkwineffects/kwineffects.cpp:522
#24 0x00007fe36b73adda in KWin::EffectsHandlerImpl::paintScreen (this=0x26778e0, mask=8, region=..., data=...) at ../../kwin/effects.cpp:372
#25 0x00007fe36b71ae83 in KWin::Scene::paintScreen (this=this@entry=0x212e380, mask=mask@entry=0x7fff0f72366c, damage=..., repaint=..., updateRegion=updateRegion@entry=0x7fff0f723680, validRegion=validRegion@entry=0x7fff0f723690) at ../../kwin/scene.cpp:148
#26 0x00007fe36b72dc7e in KWin::SceneOpenGL::paint (this=0x212e380, damage=..., toplevels=...) at ../../kwin/scene_opengl.cpp:389
#27 0x00007fe36b712af3 in KWin::Compositor::performCompositing (this=0x20edfe0) at ../../kwin/composite.cpp:624
#28 0x00007fe36575ca31 in QObject::event (this=0x20edfe0, e=<optimized out>) at kernel/qobject.cpp:1156
#29 0x00007fe364adde2c in QApplicationPrivate::notify_helper (this=this@entry=0x1f3a7e0, receiver=receiver@entry=0x20edfe0, e=e@entry=0x7fff0f723b40) at kernel/qapplication.cpp:4567
#30 0x00007fe364ae44a0 in QApplication::notify (this=this@entry=0x7fff0f724010, receiver=receiver@entry=0x20edfe0, e=e@entry=0x7fff0f723b40) at kernel/qapplication.cpp:4353
#31 0x00007fe369fcad1a in KApplication::notify (this=0x7fff0f724010, receiver=0x20edfe0, event=0x7fff0f723b40) at ../../kdeui/kernel/kapplication.cpp:311
#32 0x00007fe3657444dd in QCoreApplication::notifyInternal (this=0x7fff0f724010, receiver=0x20edfe0, event=0x7fff0f723b40) at kernel/qcoreapplication.cpp:953
#33 0x00007fe365774323 in sendEvent (event=<optimized out>, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:231
#34 QTimerInfoList::activateTimers (this=0x1f3b588) at kernel/qeventdispatcher_unix.cpp:621
#35 0x00007fe3657743a0 in QEventDispatcherUNIX::activateTimers (this=this@entry=0x1f3a770) at kernel/qeventdispatcher_unix.cpp:878
#36 0x00007fe365774d20 in QEventDispatcherUNIX::processEvents (this=this@entry=0x1f3a770, flags=...) at kernel/qeventdispatcher_unix.cpp:940
#37 0x00007fe364b804d6 in QEventDispatcherX11::processEvents (this=0x1f3a770, flags=...) at kernel/qeventdispatcher_x11.cpp:152
#38 0x00007fe3657430af in QEventLoop::processEvents (this=this@entry=0x7fff0f723e80, flags=...) at kernel/qeventloop.cpp:149
#39 0x00007fe3657433a5 in QEventLoop::exec (this=this@entry=0x7fff0f723e80, flags=...) at kernel/qeventloop.cpp:204
#40 0x00007fe365748b79 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1225
#41 0x00007fe364adc37c in QApplication::exec () at kernel/qapplication.cpp:3828
#42 0x00007fe36b6cc9d6 in kdemain (argc=3, argv=0x7fff0f724158) at ../../kwin/main.cpp:597
#43 0x00007fe36b2adec5 in __libc_start_main (main=0x4006d0 <main(int, char**)>, argc=3, argv=0x7fff0f724158, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fff0f724148) at libc-start.c:287
#44 0x00000000004006fe in _start ()

Possible duplicates by query: bug 340808, bug 335225, bug 335224, bug 333332, bug 333327.



Reproducible: Couldn't Reproduce

Steps to Reproduce:
1. Installed Eclipse and was in the process of adding custom plugins.
2.
3.

Actual Results:  
Could not reproduce.

Expected Results:  
N/A

Hopefully the traceback will be enough for you. I'll update this ticket if it happens again.

Keep up the great work. Thank you.