SUMMARY
Kdenlive crashes when opening a saved project.
(Also I post this manually because Dr. Konqi seems also unable to submit bug reporsts "Could not send error report" or "Did not receive a token")

STEPS TO REPRODUCE
1. Create a new project
2. Save the project
3. Close Project
4. Reopen Project

OBSERVED RESULT
The application crashes

EXPECTED RESULT
The applications opens and loads the opened project

Dr. Konqi Error report:

Application: kdenlive (19.12.1)

Qt Version: 5.14.0
Frameworks Version: 5.66.0
Operating System: Linux 5.4.12-1-default x86_64
Distribution: "openSUSE Tumbleweed"

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

Opened a recently save project by the same version of KDEnlive

The crash can be reproduced every time.

-- Backtrace:
Application: Kdenlive (kdenlive), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
[Current thread is 1 (Thread 0x7ff5808d9c80 (LWP 8539))]

Thread 16 (Thread 0x7ff51f7fe700 (LWP 8557)):
#0  0x00007ff585697bdf in poll () at /lib64/libc.so.6
#1  0x00007ff5810422ee in  () at /usr/lib64/libglib-2.0.so.0
#2  0x00007ff58104240f in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#3  0x00007ff582b67bdb in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7ff50c000b60, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#4  0x00007ff582b0fd5b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7ff51f7fdda0, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:136
#5  0x00007ff58293b63e in QThread::exec() (this=<optimized out>) at ../../include/QtCore/../../src/corelib/global/qflags.h:118
#6  0x00007ff58293c708 in QThreadPrivate::start(void*) (arg=0x5f4a640) at thread/qthread_unix.cpp:342
#7  0x00007ff581e8cf2a in start_thread () at /lib64/libpthread.so.0
#8  0x00007ff5856a24af in clone () at /lib64/libc.so.6

Thread 15 (Thread 0x7ff51ffff700 (LWP 8556)):
#0  0x00007ff581e936a5 in pthread_cond_wait@@GLIBC_2.3.2 () at /lib64/libpthread.so.0
#1  0x00007ff58294224b in QWaitConditionPrivate::wait(QDeadlineTimer) (deadline=..., this=0x60aff90) at thread/qwaitcondition_unix.cpp:146
#2  0x00007ff58294224b in QWaitCondition::wait(QMutex*, QDeadlineTimer) (this=<optimized out>, mutex=0x63273a0, deadline=...) at thread/qwaitcondition_unix.cpp:225
#3  0x00007ff582942309 in QWaitCondition::wait(QMutex*, unsigned long) (this=0x63273a8, mutex=0x63273a0, time=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qdeadlinetimer.h:68
#4  0x00007ff58480a21f in  () at /usr/lib64/libQt5Quick.so.5
#5  0x00007ff58480a499 in  () at /usr/lib64/libQt5Quick.so.5
#6  0x00007ff58293c708 in QThreadPrivate::start(void*) (arg=0x6327300) at thread/qthread_unix.cpp:342
#7  0x00007ff581e8cf2a in start_thread () at /lib64/libpthread.so.0
#8  0x00007ff5856a24af in clone () at /lib64/libc.so.6

Thread 14 (Thread 0x7ff548c8d700 (LWP 8555)):
#0  0x00007ff585697bdf in poll () at /lib64/libc.so.6
#1  0x00007ff5810422ee in  () at /usr/lib64/libglib-2.0.so.0
#2  0x00007ff58104240f in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#3  0x00007ff582b67bdb in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7ff518000b60, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#4  0x00007ff582b0fd5b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7ff548c8cda0, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:136
#5  0x00007ff58293b63e in QThread::exec() (this=<optimized out>) at ../../include/QtCore/../../src/corelib/global/qflags.h:118
#6  0x00007ff58293c708 in QThreadPrivate::start(void*) (arg=0x62ae5f0) at thread/qthread_unix.cpp:342
#7  0x00007ff581e8cf2a in start_thread () at /lib64/libpthread.so.0
#8  0x00007ff5856a24af in clone () at /lib64/libc.so.6

Thread 13 (Thread 0x7ff5498d1700 (LWP 8554)):
#0  0x00007ff581e936a5 in pthread_cond_wait@@GLIBC_2.3.2 () at /lib64/libpthread.so.0
#1  0x00007ff58294224b in QWaitConditionPrivate::wait(QDeadlineTimer) (deadline=..., this=0x4126560) at thread/qwaitcondition_unix.cpp:146
#2  0x00007ff58294224b in QWaitCondition::wait(QMutex*, QDeadlineTimer) (this=<optimized out>, mutex=0x60e18d0, deadline=...) at thread/qwaitcondition_unix.cpp:225
#3  0x00007ff582942309 in QWaitCondition::wait(QMutex*, unsigned long) (this=0x60e18d8, mutex=0x60e18d0, time=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qdeadlinetimer.h:68
#4  0x00007ff58480a21f in  () at /usr/lib64/libQt5Quick.so.5
#5  0x00007ff58480a499 in  () at /usr/lib64/libQt5Quick.so.5
#6  0x00007ff58293c708 in QThreadPrivate::start(void*) (arg=0x60e1830) at thread/qthread_unix.cpp:342
#7  0x00007ff581e8cf2a in start_thread () at /lib64/libpthread.so.0
#8  0x00007ff5856a24af in clone () at /lib64/libc.so.6

Thread 12 (Thread 0x7ff54b1fe700 (LWP 8550)):
#0  0x00007ff585697bdf in poll () at /lib64/libc.so.6
#1  0x00007ff5810422ee in  () at /usr/lib64/libglib-2.0.so.0
#2  0x00007ff58104240f in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#3  0x00007ff582b67bdb in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7ff538000b60, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#4  0x00007ff582b0fd5b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7ff54b1fdd60, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:136
#5  0x00007ff58293b63e in QThread::exec() (this=<optimized out>) at ../../include/QtCore/../../src/corelib/global/qflags.h:118
#6  0x00007ff5847480d6 in  () at /usr/lib64/libQt5Quick.so.5
#7  0x00007ff58293c708 in QThreadPrivate::start(void*) (arg=0x47ce2f0) at thread/qthread_unix.cpp:342
#8  0x00007ff581e8cf2a in start_thread () at /lib64/libpthread.so.0
#9  0x00007ff5856a24af in clone () at /lib64/libc.so.6

Thread 11 (Thread 0x7ff54bfff700 (LWP 8549)):
#0  0x00007ff58293cc6f in QMutex::unlock() (this=this@entry=0x45d4850) at /usr/include/c++/9/bits/atomic_base.h:769
#1  0x00007ff582b67ade in QMutexLocker::unlock() (this=<synthetic pointer>) at ../../include/QtCore/../../src/corelib/thread/qmutex.h:270
#2  0x00007ff582b67ade in QMutexLocker::~QMutexLocker() (this=<synthetic pointer>, __in_chrg=<optimized out>) at ../../include/QtCore/../../src/corelib/thread/qmutex.h:243
#3  0x00007ff582b67ade in QThreadData::canWaitLocked() (this=0x45d4820) at ../../include/QtCore/5.14.0/QtCore/private/../../../../../src/corelib/thread/qthread_p.h:272
#4  0x00007ff582b67ade in postEventSourcePrepare(GSource*, gint*) (s=0x7ff540004bb0, timeout=0x7ff54bffebb4) at kernel/qeventdispatcher_glib.cpp:260
#5  0x00007ff58104187a in g_main_context_prepare () at /usr/lib64/libglib-2.0.so.0
#6  0x00007ff58104221b in  () at /usr/lib64/libglib-2.0.so.0
#7  0x00007ff58104240f in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#8  0x00007ff582b67bdb in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7ff540000b60, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#9  0x00007ff582b0fd5b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7ff54bffed80, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:136
#10 0x00007ff58293b63e in QThread::exec() (this=<optimized out>) at ../../include/QtCore/../../src/corelib/global/qflags.h:118
#11 0x00007ff5832d4a65 in  () at /usr/lib64/libQt5Qml.so.5
#12 0x00007ff58293c708 in QThreadPrivate::start(void*) (arg=0x45d4690) at thread/qthread_unix.cpp:342
#13 0x00007ff581e8cf2a in start_thread () at /lib64/libpthread.so.0
#14 0x00007ff5856a24af in clone () at /lib64/libc.so.6

Thread 10 (Thread 0x7ff558d49700 (LWP 8548)):
#0  0x00007ff58108d5e9 in g_mutex_lock () at /usr/lib64/libglib-2.0.so.0
#1  0x00007ff5810423fa in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#2  0x00007ff582b67bdb in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7ff544000b60, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#3  0x00007ff582b0fd5b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7ff558d48d60, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:136
#4  0x00007ff58293b63e in QThread::exec() (this=<optimized out>) at ../../include/QtCore/../../src/corelib/global/qflags.h:118
#5  0x00007ff5847480d6 in  () at /usr/lib64/libQt5Quick.so.5
#6  0x00007ff58293c708 in QThreadPrivate::start(void*) (arg=0x45d1ca0) at thread/qthread_unix.cpp:342
#7  0x00007ff581e8cf2a in start_thread () at /lib64/libpthread.so.0
#8  0x00007ff5856a24af in clone () at /lib64/libc.so.6

Thread 9 (Thread 0x7ff559fbd700 (LWP 8547)):
#0  0x00007ff585697bdf in poll () at /lib64/libc.so.6
#1  0x00007ff5810422ee in  () at /usr/lib64/libglib-2.0.so.0
#2  0x00007ff58104240f in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#3  0x00007ff582b67bdb in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7ff550000b60, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#4  0x00007ff582b0fd5b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7ff559fbcd80, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:136
#5  0x00007ff58293b63e in QThread::exec() (this=<optimized out>) at ../../include/QtCore/../../src/corelib/global/qflags.h:118
#6  0x00007ff5832d4a65 in  () at /usr/lib64/libQt5Qml.so.5
#7  0x00007ff58293c708 in QThreadPrivate::start(void*) (arg=0x42ea7c0) at thread/qthread_unix.cpp:342
#8  0x00007ff581e8cf2a in start_thread () at /lib64/libpthread.so.0
#9  0x00007ff5856a24af in clone () at /lib64/libc.so.6

Thread 8 (Thread 0x7ff55b1fe700 (LWP 8546)):
#0  0x00007ff585697bdf in poll () at /lib64/libc.so.6
#1  0x00007ff5810422ee in  () at /usr/lib64/libglib-2.0.so.0
#2  0x00007ff58104240f in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#3  0x00007ff582b67bdb in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7ff54c000b60, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#4  0x00007ff582b0fd5b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7ff55b1fdd80, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:136
#5  0x00007ff58293b63e in QThread::exec() (this=<optimized out>) at ../../include/QtCore/../../src/corelib/global/qflags.h:118
#6  0x00007ff5832d4a65 in  () at /usr/lib64/libQt5Qml.so.5
#7  0x00007ff58293c708 in QThreadPrivate::start(void*) (arg=0x41b0290) at thread/qthread_unix.cpp:342
#8  0x00007ff581e8cf2a in start_thread () at /lib64/libpthread.so.0
#9  0x00007ff5856a24af in clone () at /lib64/libc.so.6

Thread 7 (Thread 0x7ff55bfff700 (LWP 8545)):
#0  0x00007ff585697bdf in poll () at /lib64/libc.so.6
#1  0x00007ff5810422ee in  () at /usr/lib64/libglib-2.0.so.0
#2  0x00007ff58104240f in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#3  0x00007ff582b67bdb in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7ff554000b60, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#4  0x00007ff582b0fd5b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7ff55bffed80, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:136
#5  0x00007ff58293b63e in QThread::exec() (this=<optimized out>) at ../../include/QtCore/../../src/corelib/global/qflags.h:118
#6  0x00007ff5832d4a65 in  () at /usr/lib64/libQt5Qml.so.5
#7  0x00007ff58293c708 in QThreadPrivate::start(void*) (arg=0x40ed690) at thread/qthread_unix.cpp:342
#8  0x00007ff581e8cf2a in start_thread () at /lib64/libpthread.so.0
#9  0x00007ff5856a24af in clone () at /lib64/libc.so.6

Thread 6 (Thread 0x7ff569bd2700 (LWP 8544)):
#0  0x00007ff581e939ca in pthread_cond_timedwait@@GLIBC_2.3.2 () at /lib64/libpthread.so.0
#1  0x00007ff5829421d4 in QWaitConditionPrivate::wait_relative(QDeadlineTimer) (this=0x3d5f820, deadline=...) at thread/qwaitcondition_unix.cpp:136
#2  0x00007ff5829421d4 in QWaitConditionPrivate::wait(QDeadlineTimer) (deadline=..., this=0x3d5f820) at thread/qwaitcondition_unix.cpp:144
#3  0x00007ff5829421d4 in QWaitCondition::wait(QMutex*, QDeadlineTimer) (this=<optimized out>, mutex=0x20334d8, deadline=...) at thread/qwaitcondition_unix.cpp:225
#4  0x00007ff5829422d7 in QWaitCondition::wait(QMutex*, unsigned long) (this=this@entry=0x3d57fe0, mutex=mutex@entry=0x20334d8, time=<optimized out>) at thread/qwaitcondition_unix.cpp:209
#5  0x00007ff58293fa4b in QThreadPoolThread::run() (this=0x3d57fd0) at ../../include/QtCore/../../src/corelib/thread/qmutex.h:270
#6  0x00007ff58293c708 in QThreadPrivate::start(void*) (arg=0x3d57fd0) at thread/qthread_unix.cpp:342
#7  0x00007ff581e8cf2a in start_thread () at /lib64/libpthread.so.0
#8  0x00007ff5856a24af in clone () at /lib64/libc.so.6

Thread 5 (Thread 0x7ff56af9b700 (LWP 8543)):
#0  0x00007ff585697bdf in poll () at /lib64/libc.so.6
#1  0x00007ff5810422ee in  () at /usr/lib64/libglib-2.0.so.0
#2  0x00007ff58104240f in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#3  0x00007ff582b67bdb in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7ff55c000b60, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#4  0x00007ff582b0fd5b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7ff56af9ad80, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:136
#5  0x00007ff58293b63e in QThread::exec() (this=<optimized out>) at ../../include/QtCore/../../src/corelib/global/qflags.h:118
#6  0x00007ff5832d4a65 in  () at /usr/lib64/libQt5Qml.so.5
#7  0x00007ff58293c708 in QThreadPrivate::start(void*) (arg=0x396cd20) at thread/qthread_unix.cpp:342
#8  0x00007ff581e8cf2a in start_thread () at /lib64/libpthread.so.0
#9  0x00007ff5856a24af in clone () at /lib64/libc.so.6

Thread 4 (Thread 0x7ff56bf8e700 (LWP 8542)):
#0  0x00007ff581e939ca in pthread_cond_timedwait@@GLIBC_2.3.2 () at /lib64/libpthread.so.0
#1  0x00007ff5829421d4 in QWaitConditionPrivate::wait_relative(QDeadlineTimer) (this=0x203b3e0, deadline=...) at thread/qwaitcondition_unix.cpp:136
#2  0x00007ff5829421d4 in QWaitConditionPrivate::wait(QDeadlineTimer) (deadline=..., this=0x203b3e0) at thread/qwaitcondition_unix.cpp:144
#3  0x00007ff5829421d4 in QWaitCondition::wait(QMutex*, QDeadlineTimer) (this=<optimized out>, mutex=0x20334d8, deadline=...) at thread/qwaitcondition_unix.cpp:225
#4  0x00007ff5829422d7 in QWaitCondition::wait(QMutex*, unsigned long) (this=this@entry=0x2030dc0, mutex=mutex@entry=0x20334d8, time=<optimized out>) at thread/qwaitcondition_unix.cpp:209
#5  0x00007ff58293fa4b in QThreadPoolThread::run() (this=0x2030db0) at ../../include/QtCore/../../src/corelib/thread/qmutex.h:270
#6  0x00007ff58293c708 in QThreadPrivate::start(void*) (arg=0x2030db0) at thread/qthread_unix.cpp:342
#7  0x00007ff581e8cf2a in start_thread () at /lib64/libpthread.so.0
#8  0x00007ff5856a24af in clone () at /lib64/libc.so.6

Thread 3 (Thread 0x7ff57dd17700 (LWP 8541)):
#0  0x00007ff58108d5e9 in g_mutex_lock () at /usr/lib64/libglib-2.0.so.0
#1  0x00007ff5810421f0 in  () at /usr/lib64/libglib-2.0.so.0
#2  0x00007ff58104240f in g_main_context_iteration () at /usr/lib64/libglib-2.0.so.0
#3  0x00007ff582b67bdb in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x7ff570000b60, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#4  0x00007ff582b0fd5b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7ff57dd16d70, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:136
#5  0x00007ff58293b63e in QThread::exec() (this=<optimized out>) at ../../include/QtCore/../../src/corelib/global/qflags.h:118
#6  0x00007ff5841fc507 in  () at /usr/lib64/libQt5DBus.so.5
#7  0x00007ff58293c708 in QThreadPrivate::start(void*) (arg=0x7ff58427eda0) at thread/qthread_unix.cpp:342
#8  0x00007ff581e8cf2a in start_thread () at /lib64/libpthread.so.0
#9  0x00007ff5856a24af in clone () at /lib64/libc.so.6

Thread 2 (Thread 0x7ff57e838700 (LWP 8540)):
#0  0x00007ff585697bdf in poll () at /lib64/libc.so.6
#1  0x00007ff580f49752 in  () at /usr/lib64/libxcb.so.1
#2  0x00007ff580f4a40a in xcb_wait_for_event () at /usr/lib64/libxcb.so.1
#3  0x00007ff57ea229a0 in  () at /usr/lib64/libQt5XcbQpa.so.5
#4  0x00007ff58293c708 in QThreadPrivate::start(void*) (arg=0x178c5a0) at thread/qthread_unix.cpp:342
#5  0x00007ff581e8cf2a in start_thread () at /lib64/libpthread.so.0
#6  0x00007ff5856a24af in clone () at /lib64/libc.so.6

Thread 1 (Thread 0x7ff5808d9c80 (LWP 8539)):
[KCrash Handler]
#6  0x0000000000000000 in  ()
#7  0x00007ff581f774c1 in QQmlAdaptorModel::rowCount() const () at /usr/lib64/libQt5QmlModels.so.5
#8  0x00007ff581f77558 in QQmlAdaptorModel::columnAt(int) const () at /usr/lib64/libQt5QmlModels.so.5
#9  0x00007ff581f7aa14 in  () at /usr/lib64/libQt5QmlModels.so.5
#10 0x00007ff581f7fb44 in QQmlDelegateModel::modelIndex(int) const () at /usr/lib64/libQt5QmlModels.so.5
#11 0x00007ff581f8f6da in  () at /usr/lib64/libQt5QmlModels.so.5
#12 0x00007ff581f8fb73 in QQmlDelegateModel::qt_metacall(QMetaObject::Call, int, void**) () at /usr/lib64/libQt5QmlModels.so.5
#13 0x00007ff58326de7d in  () at /usr/lib64/libQt5Qml.so.5
#14 0x00007ff58314e34d in  () at /usr/lib64/libQt5Qml.so.5
#15 0x00007ff583150504 in  () at /usr/lib64/libQt5Qml.so.5
#16 0x00007ff5831512ee in QV4::QObjectMethod::callInternal(QV4::Value const*, QV4::Value const*, int) const () at /usr/lib64/libQt5Qml.so.5
#17 0x00007ff583180e2b in QV4::Runtime::CallPropertyLookup::call(QV4::ExecutionEngine*, QV4::Value const&, unsigned int, QV4::Value*, int) () at /usr/lib64/libQt5Qml.so.5
#18 0x00007ff54a17ec66 in  ()
#19 0x0000000000000000 in  ()
[Inferior 1 (process 8539) detached]

Possible duplicates by query: bug 416730, bug 416549, bug 416479, bug 416379, bug 416246.