First, DrKonqi won't report this because the F19 system reports that the KDE version is 1.0 (a problem that I've reported to them .

I had a dual monitor setup that was working with no problems. However, I needed to remove one of the monitors for use with a different computer. That was done while this system was turned off. When it was rebooted, I realized that I needed to tell the display settings that there was now only one monitor. So I went to the system settings screen, and selected the Display and Monitor item. When I did that, the the system settings application crashed.

I will try to put the DrKonqi kcrash file into the additional comments section below. 

Reproducible: Always

Steps to Reproduce:
1. Start SystemSettings
2. Select Display and Monitor
3.
Actual Results:  
Crash

Expected Results:  
kcm_randr display

pplication: KDE Daemon (kded4), signal SIGABRT
0x00000031f5ea3e61 in nanosleep () from /lib64/libc.so.6
[Current thread is 1 (Thread 0x7fdc5e87b820 (LWP 2906))]

Thread 2 (Thread 0x7fdc4c973910 (LWP 3026)):
#0  0x00000031f5ed4f73 in *__GI___poll (fds=<value optimized out>, nfds=<value optimized out>, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:87
#1  0x00000030b803b05c in ?? () from /lib64/libglib-2.0.so.0
#2  0x00000030b803b3a0 in g_main_context_iteration () from /lib64/libglib-2.0.so.0
#3  0x000000347bf6840e in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQtCore.so.4
#4  0x000000347bf3e5f2 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQtCore.so.4
#5  0x000000347bf3e9c4 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQtCore.so.4
#6  0x000000347be56f6b in QThread::exec() () from /usr/lib64/libQtCore.so.4
#7  0x000000347bf21f08 in ?? () from /usr/lib64/libQtCore.so.4
#8  0x000000347be59cd5 in ?? () from /usr/lib64/libQtCore.so.4
#9  0x00000031f6e0686a in start_thread (arg=<value optimized out>) at pthread_create.c:297
#10 0x00000031f5ede25d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#11 0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7fdc5e87b820 (LWP 2906)):
[KCrash Handler]
#5  0x00000031f5e332f5 in *__GI_raise (sig=<value optimized out>) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
#6  0x00000031f5e34b20 in *__GI_abort () at abort.c:88
#7  0x00000031f5e7005d in __libc_message (do_abort=2, 
    fmt=0x7fff4cf24220 "config/beeeeb3dfe132a8a0633a017c99ce0c0-x86-64.cache-2\n7fdc5e8bf000-7fdc5e8c6000 r--s 00000000 fd:00 787341", ' ' <repeats 21 times>, "/usr/lib64/gconv/gconv-modules.cache\n7fdc5e8c6000-7fdc5e8c8000 rw-p 7fdc"...) at ../sysdeps/unix/sysv/linux/libc_fatal.c:170
#8  0x00000031f5e75a26 in malloc_printerr (action=3, str=0x31f5f35d48 "double free or corruption (!prev)", ptr=<value optimized out>) at malloc.c:6196
#9  0x000000347be9c9dc in QString::free(QString::Data*) () from /usr/lib64/libQtCore.so.4
#10 0x00000030674b2fc9 in ?? () from /usr/lib64/libkio.so.5
#11 0x00000030675213b7 in ?? () from /usr/lib64/libkio.so.5
#12 0x000000306752142e in KDirWatch::~KDirWatch() () from /usr/lib64/libkio.so.5
#13 0x0000003066606235 in KLibrary::resolveFunction(char const*) () from /usr/lib64/libkdeinit4_kded4.so
#14 0x00000030666084e5 in KLibrary::resolveFunction(char const*) () from /usr/lib64/libkdeinit4_kded4.so
#15 0x000000306660aa54 in KLibrary::resolveFunction(char const*) () from /usr/lib64/libkdeinit4_kded4.so
#16 0x000000347bf54fdc in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib64/libQtCore.so.4
#17 0x000000347bf4ef93 in QObject::event(QEvent*) () from /usr/lib64/libQtCore.so.4
#18 0x0000003068b8ee2c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib64/libQtGui.so.4
#19 0x0000003068b95e5e in QApplication::notify(QObject*, QEvent*) () from /usr/lib64/libQtGui.so.4
#20 0x0000003066204b16 in KApplication::notify(QObject*, QEvent*) () from /usr/lib64/libkdeui.so.5
#21 0x000000347bf3fcbc in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib64/libQtCore.so.4
#22 0x000000347bf6aa72 in ?? () from /usr/lib64/libQtCore.so.4
#23 0x000000347bf6846d in ?? () from /usr/lib64/libQtCore.so.4
#24 0x00000030b8037abe in g_main_context_dispatch () from /lib64/libglib-2.0.so.0
#25 0x00000030b803b278 in ?? () from /lib64/libglib-2.0.so.0
#26 0x00000030b803b3a0 in g_main_context_iteration () from /lib64/libglib-2.0.so.0
#27 0x000000347bf683b6 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQtCore.so.4
#28 0x0000003068c21b6e in ?? () from /usr/lib64/libQtGui.so.4
#29 0x000000347bf3e5f2 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQtCore.so.4
#30 0x000000347bf3e9c4 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQtCore.so.4
#31 0x000000347bf40b79 in QCoreApplication::exec() () from /usr/lib64/libQtCore.so.4
#32 0x000000306660b37b in kdemain () from /usr/lib64/libkdeinit4_kded4.so
#33 0x00000031f5e1ea2d in __libc_start_main (main=<value optimized out>, argc=<value optimized out>, ubp_av=<value optimized out>, init=<value optimized out>, fini=<value optimized out>, 
    rtld_fini=<value optimized out>, stack_end=0x7fff4cf25908) at libc-start.c:220
#34 0x0000000000400709 in _start ()
Current language:  auto; currently minimal

Application: systemsettings (1.0)
KDE Platform Version: 4.10.1
Qt Version: 4.8.4
Operating System: Linux 3.9.0-0.rc4.git0.1.fc19.x86_64 x86_64
Distribution: "Fedora release 19 (Schrödinger’s Cat)"

-- Information about the crash:
Trying to adjust my display settings because one of my two monitors has been removed from this system

The crash can be reproduced every time.

-- Backtrace:
Application: System Settings (systemsettings), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
81      T_PSEUDO (SYSCALL_SYMBOL, SYSCALL_NAME, SYSCALL_NARGS)
[Current thread is 1 (Thread 0x7f845d3af8c0 (LWP 22425))]

Thread 2 (Thread 0x7f844ec70700 (LWP 22435)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00000038f018652b in QTWTF::TCMalloc_PageHeap::scavengerThread (this=0x38f0483f00 <QTWTF::pageheap_memory>) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:2359
#2  0x00000038f0186569 in QTWTF::TCMalloc_PageHeap::runScavengerThread (context=<optimized out>) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:1464
#3  0x0000003de2c07c53 in start_thread (arg=0x7f844ec70700) at pthread_create.c:308
#4  0x0000003de24f4ecd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:113

Thread 1 (Thread 0x7f845d3af8c0 (LWP 22425)):
[KCrash Handler]
#6  ref (this=0x51000000000000) at /usr/include/QtCore/qatomic_x86_64.h:121
#7  QString (other=..., this=this@entry=0x7fffa7554ae0) at /usr/include/QtCore/qstring.h:726
#8  KScreen::Mode::name (this=0x2817980) at /usr/src/debug/libkscreen-0.0.81/src/mode.cpp:66
#9  0x00007f844f0a7f43 in QMLOutput::setOutput (this=this@entry=0x2aa5320, output=0x2816ba0) at /usr/src/debug/kscreen-0.0.71/kcm/src/qmloutput.cpp:55
#10 0x00007f844f0a122f in QMLOutput::qt_metacall (this=0x2aa5320, _c=QMetaObject::WriteProperty, _id=0, _a=0x7fffa7554d00) at /usr/src/debug/kscreen-0.0.71/x86_64-redhat-linux-gnu/kcm/src/moc_qmloutput.cpp:141
#11 0x00000030039a4b19 in QDeclarativeVMEMetaObject::metaCall (this=0x2ac1f60, c=QMetaObject::WriteProperty, _id=41, a=0x7fffa7554d00) at qml/qdeclarativevmemetaobject.cpp:673
#12 0x00000030039c07de in QDeclarativePropertyPrivate::write (object=object@entry=0x2aa5320, property=..., value=..., context=<optimized out>, flags=...) at qml/qdeclarativeproperty.cpp:1176
#13 0x0000003003a4814b in QDeclarativeObjectScriptClass::setProperty (this=0x2835ae0, obj=0x2aa5320, name=<optimized out>, value=..., context=0x7f83cdf700c0, evalContext=<optimized out>) at qml/qdeclarativeobjectscriptclass.cpp:439
#14 0x00000038f01fdc58 in QScript::DeclarativeObjectDelegate::put (this=0x2b04220, object=0x7f83cdf14080, exec=<optimized out>, propertyName=..., value=..., slot=...) at bridge/qscriptdeclarativeobject.cpp:99
#15 0x00000038f01c2a6b in QScriptEnginePrivate::setProperty (exec=exec@entry=0x7f83cdf700c0, objectValue=..., id=..., value=value@entry=..., flags=...) at api/qscriptengine.cpp:1861
#16 0x00000038f01e0331 in setProperty (flags=..., value=<synthetic pointer>, name=..., this=0x2a96ef0) at api/qscriptengine_p.h:791
#17 QScriptValue::setProperty (this=this@entry=0x7fffa7555050, name=..., value=..., flags=...) at api/qscriptvalue.cpp:1366
#18 0x00000030039c27f2 in QDeclarativeComponentPrivate::createObject (this=this@entry=0x2a7a710, publicParent=publicParent@entry=0x2979ac0, valuemap=...) at qml/qdeclarativecomponent.cpp:742
#19 0x00000030039c2b59 in QDeclarativeComponent::createObject (this=0x2a7a240, parent=0x2979ac0, valuemap=...) at qml/qdeclarativecomponent.cpp:682
#20 0x0000003003aaeec9 in QDeclarativeComponent::qt_static_metacall (_o=0x7fffa7554ae0, _o@entry=0x2a7a240, _c=42039680, _c@entry=QMetaObject::InvokeMetaMethod, _id=0, _id@entry=4, _a=0x7fffa7555390) at .moc/release-shared/moc_qdeclarativecomponent.cpp:96
#21 0x0000003003aaf0af in QDeclarativeComponent::qt_metacall (this=0x2a7a240, _c=QMetaObject::InvokeMetaMethod, _id=4, _a=0x7fffa7555390) at .moc/release-shared/moc_qdeclarativecomponent.cpp:136
#22 0x0000003003a49818 in QDeclarativeObjectMethodScriptClass::callMethod (this=this@entry=0x2835af0, object=object@entry=0x2a7a240, index=<optimized out>, returnType=<optimized out>, argCount=<optimized out>, argTypes=0x7fffa7555640, ctxt=ctxt@entry=0x7f83cdf700c0) at qml/qdeclarativeobjectscriptclass.cpp:970
#23 0x0000003003a4b4a8 in QDeclarativeObjectMethodScriptClass::callPrecise (this=this@entry=0x2835af0, object=0x2a7a240, data=..., ctxt=ctxt@entry=0x7f83cdf700c0) at qml/qdeclarativeobjectscriptclass.cpp:944
#24 0x0000003003a4bafd in QDeclarativeObjectMethodScriptClass::callOverloaded (this=0x2835af0, method=0x2a8eac0, ctxt=0x7f83cdf700c0) at qml/qdeclarativeobjectscriptclass.cpp:1064
#25 0x0000003003a4bd8f in QDeclarativeObjectMethodScriptClass::call (this=<optimized out>, o=<optimized out>, ctxt=<optimized out>) at qml/qdeclarativeobjectscriptclass.cpp:919
#26 0x00000038f01fd824 in QScript::DeclarativeObjectDelegate::call (exec=<optimized out>, callee=<optimized out>, thisValue=..., args=...) at bridge/qscriptdeclarativeobject.cpp:154
#27 0x00000038f00f8298 in QTJSC::NativeFuncWrapper::operator() (this=this@entry=0x7fffa7555910, exec=0x7f83cdf700c0, jsobj=jsobj@entry=0x7f83cdf0f840, thisValue=..., argList=...) at ../3rdparty/javascriptcore/JavaScriptCore/runtime/CallData.cpp:46
#28 0x00000038f00d6140 in QTJSC::cti_op_call_NotJSFunction (args=0x7fffa7555960) at ../3rdparty/javascriptcore/JavaScriptCore/jit/JITStubs.cpp:1780
#29 0x00007f83ce3853ea in ?? ()
#30 0x0000000000000000 in ?? ()