100% repro
Steps to repro: 1. open activity monitor.
2. click the settings for any mode
3.create duplicate windows by clicking the icon twice
4. make changes on one that is different (create discrepancy)
5. close windows (crash)

Reproducible: Always

Steps to Reproduce:
1. open activity monitor.
2.click the settings for any mode
3..create duplicate windows by clicking the icon twice
4.make changes on one that is different (create discrepancy)
5.close windows (crash)
Actual Results:  
Application: Plasma Desktop Shell (plasma-desktop), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
[Current thread is 1 (Thread 0x7fceabd54780 (LWP 1593))]

Thread 4 (Thread 0x7fce8c103700 (LWP 1595)):
#0  0x00007fceaa60f0af in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1  0x00007fce9c8028cb in QTWTF::TCMalloc_PageHeap::scavengerThread (this=0x7fce9cb00f00 <QTWTF::pageheap_memory>) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:2359
#2  0x00007fce9c802909 in QTWTF::TCMalloc_PageHeap::runScavengerThread (context=<optimized out>) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:1464
#3  0x00007fceaa60b0db in start_thread () from /lib64/libpthread.so.0
#4  0x00007fcea937490d in clone () from /lib64/libc.so.6

Thread 3 (Thread 0x7fce009f0700 (LWP 1596)):
#0  0x00007fceaa9cf03a in testAndSetOrdered (newValue=1, expectedValue=0, this=0x234d110) at ../../src/corelib/arch/qatomic_x86_64.h:145
#1  testAndSetAcquire (newValue=1, expectedValue=0, this=0x234d110) at ../../src/corelib/arch/qatomic_x86_64.h:267
#2  tryLockInline (this=0x23505d8) at ../../src/corelib/thread/qmutex.h:181
#3  lockInline (this=0x23505d8) at ../../src/corelib/thread/qmutex.h:189
#4  QMutexLocker (m=0x23505d8, this=<synthetic pointer>) at ../../src/corelib/thread/qmutex.h:109
#5  canWaitLocked (this=0x2350590) at ../../src/corelib/thread/qthread_p.h:227
#6  postEventSourcePrepare (s=0x7fcdfc0012d0, timeout=0x7fce009efc64) at kernel/qeventdispatcher_glib.cpp:263
#7  0x00007fcea627ec6d in g_main_context_prepare () from /usr/lib64/libglib-2.0.so.0
#8  0x00007fcea627f4e3 in ?? () from /usr/lib64/libglib-2.0.so.0
#9  0x00007fcea627f6cc in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
#10 0x00007fceaa9ced76 in QEventDispatcherGlib::processEvents (this=0x7fcdfc0008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:427
#11 0x00007fceaa9a0d0f in QEventLoop::processEvents (this=this@entry=0x7fce009efe20, flags=...) at kernel/qeventloop.cpp:149
#12 0x00007fceaa9a1005 in QEventLoop::exec (this=this@entry=0x7fce009efe20, flags=...) at kernel/qeventloop.cpp:204
#13 0x00007fceaa89ffef in QThread::exec (this=this@entry=0x18f33d0) at thread/qthread.cpp:536
#14 0x00007fceaa982513 in QInotifyFileSystemWatcherEngine::run (this=0x18f33d0) at io/qfilesystemwatcher_inotify.cpp:256
#15 0x00007fceaa8a268f in QThreadPrivate::start (arg=0x18f33d0) at thread/qthread_unix.cpp:338
#16 0x00007fceaa60b0db in start_thread () from /lib64/libpthread.so.0
#17 0x00007fcea937490d in clone () from /lib64/libc.so.6

Thread 2 (Thread 0x7fcdfb962700 (LWP 1597)):
#0  0x00007fcea936bb3d in poll () from /lib64/libc.so.6
#1  0x00007fcea627f5c4 in ?? () from /usr/lib64/libglib-2.0.so.0
#2  0x00007fcea627f6cc in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
#3  0x00007fceaa9ced76 in QEventDispatcherGlib::processEvents (this=0x7fcdf40008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:427
#4  0x00007fceaa9a0d0f in QEventLoop::processEvents (this=this@entry=0x7fcdfb961e20, flags=...) at kernel/qeventloop.cpp:149
#5  0x00007fceaa9a1005 in QEventLoop::exec (this=this@entry=0x7fcdfb961e20, flags=...) at kernel/qeventloop.cpp:204
#6  0x00007fceaa89ffef in QThread::exec (this=this@entry=0x24da420) at thread/qthread.cpp:536
#7  0x00007fceaa982513 in QInotifyFileSystemWatcherEngine::run (this=0x24da420) at io/qfilesystemwatcher_inotify.cpp:256
#8  0x00007fceaa8a268f in QThreadPrivate::start (arg=0x24da420) at thread/qthread_unix.cpp:338
#9  0x00007fceaa60b0db in start_thread () from /lib64/libpthread.so.0
#10 0x00007fcea937490d in clone () from /lib64/libc.so.6

Thread 1 (Thread 0x7fceabd54780 (LWP 1593)):
[KCrash Handler]
#5  allocateScriptValuePrivate (size=64, this=0x7fceaa5c7e90 <vtable for QRasterPixmapData+16>) at api/qscriptengine_p.h:596
#6  operator new (engine=0x7fceaa5c7e90 <vtable for QRasterPixmapData+16>, size=64) at api/qscriptengine_p.h:797
#7  QScriptEnginePrivate::scriptValueFromJSCValue (this=0x7fceaa5c7e90 <vtable for QRasterPixmapData+16>, value=...) at api/qscriptengine_p.h:646
#8  0x00007fce9c85bf74 in QScriptValue::call (this=this@entry=0x29e0428, thisObject=..., args=...) at api/qscriptvalue.cpp:1610
#9  0x00007fce9c0491e7 in QDeclarativeQtScriptExpression::eval (this=this@entry=0x29e03d8, secondaryScope=<optimized out>, isUndefined=0x0) at qml/qdeclarativeexpression.cpp:518
#10 0x00007fce9c04b4fe in QDeclarativeQtScriptExpression::scriptValue (this=this@entry=0x29e03d8, secondaryScope=secondaryScope@entry=0x0, isUndefined=isUndefined@entry=0x0) at qml/qdeclarativeexpression.cpp:470
#11 0x00007fce9c04b805 in QDeclarativeExpressionPrivate::scriptValue (this=this@entry=0x29e0350, secondaryScope=secondaryScope@entry=0x0, isUndefined=0x0) at qml/qdeclarativeexpression.cpp:653
#12 0x00007fce9c04b941 in QDeclarativeExpressionPrivate::value (this=0x29e0350, secondaryScope=0x0, isUndefined=isUndefined@entry=0x0) at qml/qdeclarativeexpression.cpp:667
#13 0x00007fce9c082f85 in QDeclarativeBoundSignal::qt_metacall (this=0x548fa40, c=<optimized out>, id=<optimized out>, a=0x7fff6352a2a0) at qml/qdeclarativeboundsignal.cpp:199
#14 0x00007fceaa9b5f62 in QMetaObject::activate (sender=0x2d67a60, m=<optimized out>, local_signal_index=<optimized out>, argv=argv@entry=0x7fff6352a2a0) at kernel/qobject.cpp:3586
#15 0x00007fceaa9b6713 in QMetaObject::activate (sender=<optimized out>, signal_index=signal_index@entry=40, argv=argv@entry=0x7fff6352a2a0) at kernel/qobject.cpp:3643
#16 0x00007fce9c0371ac in QDeclarativeVMEMetaObject::metaCall (this=0x29bd450, c=QMetaObject::InvokeMetaMethod, _id=40, a=0x7fff6352a2a0) at qml/qdeclarativevmemetaobject.cpp:639
#17 0x00007fce9c0dc9fe in QDeclarativeObjectMethodScriptClass::callMethod (this=this@entry=0x501e2a0, object=0x2d67a60, index=40, returnType=0, argCount=argCount@entry=0, argTypes=argTypes@entry=0x0, ctxt=ctxt@entry=0x7fcdf08fa4a8) at qml/qdeclarativeobjectscriptclass.cpp:988
#18 0x00007fce9c0de083 in QDeclarativeObjectMethodScriptClass::callPrecise (this=0x501e2a0, object=0x2d67a60, data=..., ctxt=0x7fcdf08fa4a8) at qml/qdeclarativeobjectscriptclass.cpp:948
#19 0x00007fce9c0deafb in QDeclarativeObjectMethodScriptClass::call (this=<optimized out>, o=<optimized out>, ctxt=<optimized out>) at qml/qdeclarativeobjectscriptclass.cpp:917
#20 0x00007fce9c879b14 in QScript::DeclarativeObjectDelegate::call (exec=<optimized out>, callee=<optimized out>, thisValue=..., args=...) at bridge/qscriptdeclarativeobject.cpp:154
#21 0x00007fce9c774dc8 in QTJSC::NativeFuncWrapper::operator() (this=this@entry=0x7fff6352a6d0, exec=0x7fcdf08fa4a8, jsobj=jsobj@entry=0x7fce04db3540, thisValue=..., argList=...) at ../3rdparty/javascriptcore/JavaScriptCore/runtime/CallData.cpp:46
#22 0x00007fce9c752d50 in QTJSC::cti_op_call_NotJSFunction (args=0x7fff6352a720) at ../3rdparty/javascriptcore/JavaScriptCore/jit/JITStubs.cpp:1780
#23 0x00007fce0b9bd9f3 in ?? ()
#24 0x00007fcdf9e67800 in ?? ()
#25 0x00007fce04db3540 in ?? ()
#26 0x00007fcd0000000a in ?? ()
#27 0x0000000000000001 in ?? ()
#28 0x0000000000000001 in ?? ()
#29 0x00007fceaa10e77a in QGraphicsSceneIndexRectIntersector::intersect (this=0x1f8, item=0x7fff6352a7c0, exposeRect=..., mode=4035945560, deviceTransform=...) at graphicsview/qgraphicssceneindex.cpp:106
#30 0x00007fce9c049271 in QDeclarativeQtScriptExpression::eval (this=0x7fcdf1b189d8, secondaryScope=<optimized out>, isUndefined=0x7fce04d85840) at qml/qdeclarativeexpression.cpp:515
#31 0x0000000000000000 in ?? ()


Expected Results:  
no crash, loose changes if changes were not applied.  If changes were applied then the window that was open/active during apply of changes to be saved.  Whichever window is activated and applied to keep changes and losing discrepancy of the inactive window.