Application: calligraplan (2.9.11)
KDE Platform Version: 4.14.25
Qt Version: 4.8.6
Operating System: Linux 4.4.87-18.29-default x86_64
Distribution: "openSUSE Leap 42.2"

-- Information about the crash:
I was using plan to help me prioritize some tasks.  Just a pretty simple todo list.  I was editing the list and adding tasks and rearranging the tasks and learning about plan. In particular, I was testing printing and flaging features.  After a time, I noticed the work had become corrupted.  By that I mean that the order of the tasks in the edit mode was different from the order of the tasks as displayed in the graphics mode.  I thought closing and opening the program might clear that up.  No.  Now that file crashes the program every time an attempt to open it is made.

I will send the file with this report if that is possible, otherwise, if you are interested in it, you may request it.

The crash can be reproduced every time.

-- Backtrace:
Application: Plan (calligraplan), signal: Aborted
Using host libthread_db library "/lib64/libthread_db.so.1".
[KCrash Handler]
#6  0x00007fe4fe45f8d7 in raise () from /lib64/libc.so.6
#7  0x00007fe4fe460caa in abort () from /lib64/libc.so.6
#8  0x00007fe4fe49d1b4 in __libc_message () from /lib64/libc.so.6
#9  0x00007fe4fe4a2706 in malloc_printerr () from /lib64/libc.so.6
#10 0x00007fe4fe4a3453 in _int_free () from /lib64/libc.so.6
#11 0x00007fe4fcb8bd68 in QString::free (d=0x3450034) at tools/qstring.cpp:1235
#12 0x00007fe4e99a9b79 in QString::~QString (this=0x7ffd0bf10040, __in_chrg=<optimized out>) at /usr/include/QtCore/qstring.h:880
#13 KPlato::Report::findReportData (lst=..., type=...) at /usr/src/debug/calligra-2.9.11/plan/libs/ui/reports/reportdata.cpp:85
#14 0x00007fe4e99a2c75 in KPlato::ReportDesigner::setReportData (this=0x33ac9a0, tag=...) at /usr/src/debug/calligra-2.9.11/plan/libs/ui/reports/reportview.cpp:1254
#15 0x00007fe4fcc590ea in QMetaObject::activate (sender=sender@entry=0x33b8af0, m=m@entry=0x7fe4e9c9a4e0 <KPlato::ReportSourceEditor::staticMetaObject>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x7ffd0bf101c0) at kernel/qobject.cpp:3576
#16 0x00007fe4e9998792 in KPlato::ReportSourceEditor::selectFromChanged (this=this@entry=0x33b8af0, _t1=...) at /usr/src/debug/calligra-2.9.11/build/plan/libs/ui/moc_reportsourceeditor.cpp:105
#17 0x00007fe4e99ae60f in KPlato::ReportSourceEditor::slotCurrentIndexChanged (this=0x33b8af0) at /usr/src/debug/calligra-2.9.11/plan/libs/ui/reports/reportsourceeditor.cpp:49
#18 0x00007fe4e9998736 in KPlato::ReportSourceEditor::qt_static_metacall (_o=<optimized out>, _c=<optimized out>, _id=<optimized out>, _a=<optimized out>) at /usr/src/debug/calligra-2.9.11/build/plan/libs/ui/moc_reportsourceeditor.cpp:54
#19 0x00007fe4fcc590ea in QMetaObject::activate (sender=sender@entry=0x33bae80, m=m@entry=0x7fe4fe0fdd80 <QComboBox::staticMetaObject>, local_signal_index=local_signal_index@entry=5, argv=argv@entry=0x7ffd0bf10340) at kernel/qobject.cpp:3576
#20 0x00007fe4fda144b1 in QComboBox::currentIndexChanged (this=this@entry=0x33bae80, _t1=1) at .moc/release-shared/moc_qcombobox.cpp:315
#21 0x00007fe4fda14511 in QComboBoxPrivate::_q_emitCurrentIndexChanged (this=this@entry=0x33baeb0, index=...) at widgets/qcombobox.cpp:1278
#22 0x00007fe4fda147bc in QComboBoxPrivate::setCurrentIndex (this=this@entry=0x33baeb0, mi=...) at widgets/qcombobox.cpp:2049
#23 0x00007fe4fda14a0f in QComboBox::setCurrentIndex (this=<optimized out>, index=index@entry=1) at widgets/qcombobox.cpp:2025
#24 0x00007fe4e99aeb0f in KPlato::ReportSourceEditor::setSourceData (this=0x33b8af0, element=...) at /usr/src/debug/calligra-2.9.11/plan/libs/ui/reports/reportsourceeditor.cpp:74
#25 0x00007fe4e99a2def in KPlato::ReportDesigner::setData (this=this@entry=0x33ac9a0) at /usr/src/debug/calligra-2.9.11/plan/libs/ui/reports/reportview.cpp:1129
#26 0x00007fe4e99a3020 in KPlato::ReportDesigner::setData (this=this@entry=0x33ac9a0, doc=...) at /usr/src/debug/calligra-2.9.11/plan/libs/ui/reports/reportview.cpp:1115
#27 0x00007fe4e99a34f0 in KPlato::ReportDesigner::loadContext (this=0x33ac9a0, context=...) at /usr/src/debug/calligra-2.9.11/plan/libs/ui/reports/reportview.cpp:1347
#28 0x00007fe4e999a594 in KPlato::ReportView::loadContext (this=this@entry=0x334fdd0, context=...) at /usr/src/debug/calligra-2.9.11/plan/libs/ui/reports/reportview.cpp:240
#29 0x00007fe4e9d23e8a in KPlato::View::createViews (this=this@entry=0x1b149f0) at /usr/src/debug/calligra-2.9.11/plan/kptview.cpp:539
#30 0x00007fe4e9d246ae in KPlato::View::initiateViews (this=0x1b149f0) at /usr/src/debug/calligra-2.9.11/plan/kptview.cpp:444
#31 0x00007fe4e9d261d5 in KPlato::View::qt_static_metacall (_o=0x1b149f0, _id=<optimized out>, _a=<optimized out>, _c=<optimized out>) at /usr/src/debug/calligra-2.9.11/build/plan/kptview.moc:426
#32 0x00007fe4fcc590ea in QMetaObject::activate (sender=sender@entry=0x2543260, m=m@entry=0x7fe4fcfa6d40 <QSingleShotTimer::staticMetaObject>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x0) at kernel/qobject.cpp:3576
#33 0x00007fe4fcc61f5a in QSingleShotTimer::timeout (this=0x2543260) at .moc/release-shared/qtimer.moc:96
#34 QSingleShotTimer::timerEvent (this=0x2543260) at kernel/qtimer.cpp:317
#35 0x00007fe4fcc5d2a1 in QObject::event (this=0x2543260, e=<optimized out>) at kernel/qobject.cpp:1193
#36 0x00007fe4fd64f6fc in QApplicationPrivate::notify_helper (this=this@entry=0x1a92320, receiver=receiver@entry=0x2543260, e=e@entry=0x7ffd0bf10de0) at kernel/qapplication.cpp:4565
#37 0x00007fe4fd655c3d in QApplication::notify (this=0x7ffd0bf110c0, receiver=receiver@entry=0x2543260, e=e@entry=0x7ffd0bf10de0) at kernel/qapplication.cpp:4351
#38 0x00007fe4fe180dd7 in KoApplication::notify (this=<optimized out>, receiver=0x2543260, event=0x7ffd0bf10de0) at /usr/src/debug/calligra-2.9.11/libs/main/KoApplication.cpp:625
#39 0x00007fe4fcc4517d in QCoreApplication::notifyInternal (this=0x7ffd0bf110c0, receiver=0x2543260, event=event@entry=0x7ffd0bf10de0) at kernel/qcoreapplication.cpp:953
#40 0x00007fe4fcc74bac in QCoreApplication::sendEvent (event=0x7ffd0bf10de0, receiver=<optimized out>) at kernel/qcoreapplication.h:231
#41 QTimerInfoList::activateTimers (this=0x1a97d00) at kernel/qeventdispatcher_unix.cpp:636
#42 0x00007fe4fcc71df1 in timerSourceDispatch (source=<optimized out>) at kernel/qeventdispatcher_glib.cpp:193
#43 0x00007fe4f9947134 in g_main_context_dispatch () from /usr/lib64/libglib-2.0.so.0
#44 0x00007fe4f9947388 in ?? () from /usr/lib64/libglib-2.0.so.0
#45 0x00007fe4f994742c in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
#46 0x00007fe4fcc71fae in QEventDispatcherGlib::processEvents (this=0x1a4b960, flags=...) at kernel/qeventdispatcher_glib.cpp:450
#47 0x00007fe4fd6ec606 in QGuiEventDispatcherGlib::processEvents (this=<optimized out>, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#48 0x00007fe4fcc43d3f in QEventLoop::processEvents (this=this@entry=0x7ffd0bf11050, flags=...) at kernel/qeventloop.cpp:149
#49 0x00007fe4fcc44035 in QEventLoop::exec (this=this@entry=0x7ffd0bf11050, flags=...) at kernel/qeventloop.cpp:204
#50 0x00007fe4fcc49489 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1225
#51 0x00007fe4fd64decc in QApplication::exec () at kernel/qapplication.cpp:3823
#52 0x00007fe4fe7cf925 in kdemain (argc=<optimized out>, argv=<optimized out>) at /usr/src/debug/calligra-2.9.11/plan/main.cpp:72
#53 0x00007fe4fe44b6e5 in __libc_start_main () from /lib64/libc.so.6
#54 0x0000000000400759 in _start () at ../sysdeps/x86_64/start.S:118

Reported using DrKonqi