SUMMARY
Just randomly crashed out of nowhere.

OBSERVED RESULT
Application: kdeinit5 (kdeinit5), signal: Aborted

[KCrash Handler]
#4  __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:49
#5  0x00007f846aa88864 in __GI_abort () at abort.c:79
#6  0x00007f846acdec77 in qt_message_fatal (message=<synthetic pointer>..., context=...) at global/qlogging.cpp:1914
#7  QMessageLogger::fatal (this=this@entry=0x7ffd8f0257c0, msg=msg@entry=0x7f846a5f8378 "QWidget: Cannot create a QWidget without QApplication") at global/qlogging.cpp:893
#8  0x00007f846a225a86 in QWidgetPrivate::init (this=0x560c4ced0a50, parentWidget=0x0, f=...) at kernel/qwidget.cpp:981
#9  0x00007f846a4425d3 in QDialog::QDialog (this=0x560c4ced4990, parent=0x0, f=...) at dialogs/qdialog.cpp:400
#10 0x00007f84662aab73 in KMessageBox::messageBox(QWidget*, KMessageBox::DialogType, QString const&, QString const&, KGuiItem const&, KGuiItem const&, KGuiItem const&, QString const&, QFlags<KMessageBox::Option>) () from /lib/x86_64-linux-gnu/libKF5WidgetsAddons.so.5
#11 0x00007f8466350a02 in ?? () from /lib/x86_64-linux-gnu/libKF5JobWidgets.so.5
#12 0x00007f846af3410c in QObject::event (this=0x560c4ce64b30, e=0x560c4cec6640) at kernel/qobject.cpp:1314
#13 0x00007f846af0678f in doNotify (event=0x560c4cec6640, receiver=0x560c4ce64b30) at kernel/qcoreapplication.cpp:1153
#14 QCoreApplication::notify (event=<optimized out>, receiver=<optimized out>, this=<optimized out>) at kernel/qcoreapplication.cpp:1139
#15 QCoreApplication::notifyInternal2 (receiver=0x560c4ce64b30, event=0x560c4cec6640) at kernel/qcoreapplication.cpp:1063
#16 0x00007f846af097e1 in QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x560c4cdce4e0) at kernel/qcoreapplication.cpp:1817
#17 0x00007f846af60ba7 in postEventSourceDispatch (s=0x560c4ce2bf90) at kernel/qeventdispatcher_glib.cpp:277
#18 0x00007f846961c8eb in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#19 0x00007f846966fd28 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#20 0x00007f846961a023 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#21 0x00007f846af60204 in QEventDispatcherGlib::processEvents (this=0x560c4ce2c180, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#22 0x00007f846af0511b in QEventLoop::exec (this=0x7ffd8f025d60, flags=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:69
#23 0x00007f846bab6896 in ?? () from /usr/lib/x86_64-linux-gnu/qt5/plugins/kf5/kio/filenamesearch.so
#24 0x00007f846bab6b7b in ?? () from /usr/lib/x86_64-linux-gnu/qt5/plugins/kf5/kio/filenamesearch.so
#25 0x00007f846bab6b7b in ?? () from /usr/lib/x86_64-linux-gnu/qt5/plugins/kf5/kio/filenamesearch.so
#26 0x00007f846bab70ca in ?? () from /usr/lib/x86_64-linux-gnu/qt5/plugins/kf5/kio/filenamesearch.so
#27 0x00007f8466f113d6 in KIO::SlaveBase::dispatch(int, QByteArray const&) () from /usr/lib/x86_64-linux-gnu/libKF5KIOCore.so.5
#28 0x00007f8466f11eb6 in KIO::SlaveBase::dispatchLoop() () from /usr/lib/x86_64-linux-gnu/libKF5KIOCore.so.5
#29 0x00007f846bab75b2 in kdemain () from /usr/lib/x86_64-linux-gnu/qt5/plugins/kf5/kio/filenamesearch.so
#30 0x0000560c4ca8d926 in ?? ()
#31 0x0000560c4ca8f1d9 in ?? ()
#32 0x0000560c4ca8f9d7 in ?? ()
#33 0x0000560c4ca8a1ba in ?? ()
#34 0x00007f846aa8a565 in __libc_start_main (main=0x560c4ca89710, argc=3, argv=0x7ffd8f026c58, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffd8f026c48) at ../csu/libc-start.c:332
#35 0x0000560c4ca8acbe in ?? ()
[Inferior 1 (process 157039) detached]

SOFTWARE/OS VERSIONS
Operating System: Kubuntu 21.04
KDE Plasma Version: 5.22.4
KDE Frameworks Version: 5.84.0
Qt Version: 5.15.2
Kernel Version: 5.11.0-25-lowlatency (64-bit)
Graphics Platform: X11
Processors: 8 × Intel® Core™ i5-8250U CPU @ 1.60GHz
Memory: 7,6 GiB of RAM
Graphics Processor: Mesa Intel® UHD Graphics 620