SUMMARY
I started Wayland session after logout from X11, took a screenshot by pressing
shift+printscreen shortcut, then Plasma shown a notification about kdeinit5
crash.

Operating System: KDE neon Unstable Edition
KDE Plasma Version: 5.21.80
KDE Frameworks Version: 5.81.0
Qt Version: 5.15.2
Graphics Platform: Wayland

Application: kdeinit5 (kdeinit5), signal: Segmentation fault
Content of s_kcrashErrorMessage: [Current thread is 1 (Thread 0x7ff362296cc0 (LWP 27489))]
[New LWP 27490]
[New LWP 27491]
[New LWP 27492]
[New LWP 27493]
[New LWP 27494]
[New LWP 27496]
[New LWP 27497]
[New LWP 27498]
[New LWP 27499]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
0x00007ff36576aaff in __GI___poll (fds=fds@entry=0x7fff99e75f68, nfds=nfds@entry=1, timeout=timeout@entry=1000) at ../sysdeps/unix/sysv/linux/poll.c:29

Thread 10 (Thread 0x7ff3423fb700 (LWP 27499)):
#0  futex_abstimed_wait_cancelable (private=<optimized out>, abstime=0x7ff3423facd0, clockid=<optimized out>, expected=0, futex_word=0x55b4844e2130) at ../sysdeps/nptl/futex-internal.h:320
#1  __pthread_cond_wait_common (abstime=0x7ff3423facd0, clockid=<optimized out>, mutex=0x55b4844e20e0, cond=0x55b4844e2108) at pthread_cond_wait.c:520
#2  __pthread_cond_timedwait (cond=0x55b4844e2108, mutex=0x55b4844e20e0, abstime=0x7ff3423facd0) at pthread_cond_wait.c:656
#3  0x00007ff36591ace8 in QWaitConditionPrivate::wait_relative (this=0x55b4844e20e0, deadline=...) at thread/qwaitcondition_unix.cpp:136
#4  QWaitConditionPrivate::wait (deadline=..., this=0x55b4844e20e0) at thread/qwaitcondition_unix.cpp:144
#5  QWaitCondition::wait (this=this@entry=0x55b4844c8300, mutex=mutex@entry=0x55b4844be478, deadline=...) at thread/qwaitcondition_unix.cpp:225
#6  0x00007ff3659181f1 in QThreadPoolThread::run (this=0x55b4844c82f0) at ../../include/QtCore/../../src/corelib/thread/qmutex.h:270
#7  0x00007ff365914bec in QThreadPrivate::start (arg=0x55b4844c82f0) at thread/qthread_unix.cpp:329
#8  0x00007ff364cd3609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#9  0x00007ff365777293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 9 (Thread 0x7ff342bfc700 (LWP 27498)):
#0  futex_abstimed_wait_cancelable (private=<optimized out>, abstime=0x7ff342bfbcd0, clockid=<optimized out>, expected=0, futex_word=0x55b4844e1d00) at ../sysdeps/nptl/futex-internal.h:320
#1  __pthread_cond_wait_common (abstime=0x7ff342bfbcd0, clockid=<optimized out>, mutex=0x55b4844e1cb0, cond=0x55b4844e1cd8) at pthread_cond_wait.c:520
#2  __pthread_cond_timedwait (cond=0x55b4844e1cd8, mutex=0x55b4844e1cb0, abstime=0x7ff342bfbcd0) at pthread_cond_wait.c:656
#3  0x00007ff36591ace8 in QWaitConditionPrivate::wait_relative (this=0x55b4844e1cb0, deadline=...) at thread/qwaitcondition_unix.cpp:136
#4  QWaitConditionPrivate::wait (deadline=..., this=0x55b4844e1cb0) at thread/qwaitcondition_unix.cpp:144
#5  QWaitCondition::wait (this=this@entry=0x55b4844cd9e0, mutex=mutex@entry=0x55b4844be478, deadline=...) at thread/qwaitcondition_unix.cpp:225
#6  0x00007ff3659181f1 in QThreadPoolThread::run (this=0x55b4844cd9d0) at ../../include/QtCore/../../src/corelib/thread/qmutex.h:270
#7  0x00007ff365914bec in QThreadPrivate::start (arg=0x55b4844cd9d0) at thread/qthread_unix.cpp:329
#8  0x00007ff364cd3609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#9  0x00007ff365777293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 8 (Thread 0x7ff3433fd700 (LWP 27497)):
#0  futex_abstimed_wait_cancelable (private=<optimized out>, abstime=0x7ff3433fccd0, clockid=<optimized out>, expected=0, futex_word=0x55b4844cedb0) at ../sysdeps/nptl/futex-internal.h:320
#1  __pthread_cond_wait_common (abstime=0x7ff3433fccd0, clockid=<optimized out>, mutex=0x55b4844ced60, cond=0x55b4844ced88) at pthread_cond_wait.c:520
#2  __pthread_cond_timedwait (cond=0x55b4844ced88, mutex=0x55b4844ced60, abstime=0x7ff3433fccd0) at pthread_cond_wait.c:656
#3  0x00007ff36591ace8 in QWaitConditionPrivate::wait_relative (this=0x55b4844ced60, deadline=...) at thread/qwaitcondition_unix.cpp:136
#4  QWaitConditionPrivate::wait (deadline=..., this=0x55b4844ced60) at thread/qwaitcondition_unix.cpp:144
#5  QWaitCondition::wait (this=this@entry=0x55b4844c8360, mutex=mutex@entry=0x55b4844be478, deadline=...) at thread/qwaitcondition_unix.cpp:225
#6  0x00007ff3659181f1 in QThreadPoolThread::run (this=0x55b4844c8350) at ../../include/QtCore/../../src/corelib/thread/qmutex.h:270
#7  0x00007ff365914bec in QThreadPrivate::start (arg=0x55b4844c8350) at thread/qthread_unix.cpp:329
#8  0x00007ff364cd3609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#9  0x00007ff365777293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 7 (Thread 0x7ff343bfe700 (LWP 27496)):
#0  futex_abstimed_wait_cancelable (private=<optimized out>, abstime=0x7ff343bfdcd0, clockid=<optimized out>, expected=0, futex_word=0x55b4844c8480) at ../sysdeps/nptl/futex-internal.h:320
#1  __pthread_cond_wait_common (abstime=0x7ff343bfdcd0, clockid=<optimized out>, mutex=0x55b4844c8430, cond=0x55b4844c8458) at pthread_cond_wait.c:520
#2  __pthread_cond_timedwait (cond=0x55b4844c8458, mutex=0x55b4844c8430, abstime=0x7ff343bfdcd0) at pthread_cond_wait.c:656
#3  0x00007ff36591ace8 in QWaitConditionPrivate::wait_relative (this=0x55b4844c8430, deadline=...) at thread/qwaitcondition_unix.cpp:136
#4  QWaitConditionPrivate::wait (deadline=..., this=0x55b4844c8430) at thread/qwaitcondition_unix.cpp:144
#5  QWaitCondition::wait (this=this@entry=0x55b4844ce550, mutex=mutex@entry=0x55b4844be478, deadline=...) at thread/qwaitcondition_unix.cpp:225
#6  0x00007ff3659181f1 in QThreadPoolThread::run (this=0x55b4844ce540) at ../../include/QtCore/../../src/corelib/thread/qmutex.h:270
#7  0x00007ff365914bec in QThreadPrivate::start (arg=0x55b4844ce540) at thread/qthread_unix.cpp:329
#8  0x00007ff364cd3609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#9  0x00007ff365777293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 6 (Thread 0x7ff34da6d700 (LWP 27494)):
#0  0x00007ff3641b48ed in g_source_unref_internal (source=0x7ff344005180, context=0x7ff344000c20, have_lock=1) at ../../../glib/gmain.c:2184
#1  0x00007ff3641b6345 in g_source_iter_next (iter=iter@entry=0x7ff34da6cb70, source=source@entry=0x7ff34da6cb68) at ../../../glib/gmain.c:1049
#2  0x00007ff3641b7cbf in g_main_context_check (context=context@entry=0x7ff344000c20, max_priority=2147483647, fds=fds@entry=0x7ff344005240, n_fds=n_fds@entry=1) at ../../../glib/gmain.c:3860
#3  0x00007ff3641b8312 in g_main_context_iterate (context=context@entry=0x7ff344000c20, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../../../glib/gmain.c:4044
#4  0x00007ff3641b84a3 in g_main_context_iteration (context=0x7ff344000c20, may_block=may_block@entry=1) at ../../../glib/gmain.c:4108
#5  0x00007ff365b54ffb in QEventDispatcherGlib::processEvents (this=0x7ff344000b60, flags=...) at kernel/qeventdispatcher_glib.cpp:425
#6  0x00007ff365af91eb in QEventLoop::exec (this=this@entry=0x7ff34da6cd30, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:141
#7  0x00007ff365913a52 in QThread::exec (this=this@entry=0x7ff361a4dd80 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at ../../include/QtCore/../../src/corelib/global/qflags.h:121
#8  0x00007ff3619c9f4b in QDBusConnectionManager::run (this=0x7ff361a4dd80 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at qdbusconnection.cpp:179
#9  0x00007ff365914bec in QThreadPrivate::start (arg=0x7ff361a4dd80 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at thread/qthread_unix.cpp:329
#10 0x00007ff364cd3609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#11 0x00007ff365777293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 5 (Thread 0x7ff35cc3a700 (LWP 27493)):
#0  futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55b483f57bf8) at ../sysdeps/nptl/futex-internal.h:183
#1  __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x55b483f57ba8, cond=0x55b483f57bd0) at pthread_cond_wait.c:508
#2  __pthread_cond_wait (cond=0x55b483f57bd0, mutex=0x55b483f57ba8) at pthread_cond_wait.c:638
#3  0x00007ff35eb5de6b in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#4  0x00007ff35eb5da6b in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#5  0x00007ff364cd3609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#6  0x00007ff365777293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 4 (Thread 0x7ff35d43b700 (LWP 27492)):
#0  futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55b483f57bf8) at ../sysdeps/nptl/futex-internal.h:183
#1  __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x55b483f57ba8, cond=0x55b483f57bd0) at pthread_cond_wait.c:508
#2  __pthread_cond_wait (cond=0x55b483f57bd0, mutex=0x55b483f57ba8) at pthread_cond_wait.c:638
#3  0x00007ff35eb5de6b in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#4  0x00007ff35eb5da6b in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#5  0x00007ff364cd3609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#6  0x00007ff365777293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 3 (Thread 0x7ff35dc3c700 (LWP 27491)):
#0  futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55b483f57bf8) at ../sysdeps/nptl/futex-internal.h:183
#1  __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x55b483f57ba8, cond=0x55b483f57bd0) at pthread_cond_wait.c:508
#2  __pthread_cond_wait (cond=0x55b483f57bd0, mutex=0x55b483f57ba8) at pthread_cond_wait.c:638
#3  0x00007ff35eb5de6b in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#4  0x00007ff35eb5da6b in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#5  0x00007ff364cd3609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#6  0x00007ff365777293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 2 (Thread 0x7ff35e43d700 (LWP 27490)):
#0  futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x55b483f57bf8) at ../sysdeps/nptl/futex-internal.h:183
#1  __pthread_cond_wait_common (abstime=0x0, clockid=0, mutex=0x55b483f57ba8, cond=0x55b483f57bd0) at pthread_cond_wait.c:508
#2  __pthread_cond_wait (cond=0x55b483f57bd0, mutex=0x55b483f57ba8) at pthread_cond_wait.c:638
#3  0x00007ff35eb5de6b in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#4  0x00007ff35eb5da6b in ?? () from /usr/lib/x86_64-linux-gnu/dri/i965_dri.so
#5  0x00007ff364cd3609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#6  0x00007ff365777293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 1 (Thread 0x7ff362296cc0 (LWP 27489)):
[KCrash Handler]
#6  __memmove_sse2_unaligned_erms () at ../sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S:262
#7  0x00007ff3666a63d9 in memcpy (__len=36352, __src=<optimized out>, __dest=0x7ff35e5dd000) at /usr/include/x86_64-linux-gnu/bits/string_fortified.h:34
#8  ThumbnailProtocol::get (this=0x7fff99e769c0, url=...) at ./thumbnail/thumbnail.cpp:306
#9  0x00007ff361e82ab6 in KIO::SlaveBase::dispatch (this=0x7fff99e769c0, command=67, data=...) at ./src/core/slavebase.cpp:1215
#10 0x00007ff361e83156 in KIO::SlaveBase::dispatchLoop (this=this@entry=0x7fff99e769c0) at ./src/core/slavebase.cpp:336
#11 0x00007ff3666a2cc2 in kdemain (argc=<optimized out>, argv=0x55b483f19f10) at ./thumbnail/thumbnail.cpp:124
#12 0x000055b482004076 in launch (argc=4, _name=0x55b483f199d8 "/usr/lib/x86_64-linux-gnu/qt5/plugins/kf5/kio/thumbnail.so", args=0x55b483f19a87 "", cwd=<optimized out>, envc=0, envs=<optimized out>, reset_env=false, tty=0x0, avoid_loops=false, startup_id_str=0x55b482007187 "0") at ./src/kdeinit/kinit.cpp:692
#13 0x000055b4820054da in handle_launcher_request (sock=8, who=<optimized out>) at ./src/kdeinit/kinit.cpp:1130
#14 0x000055b482005eca in handle_requests (waitForPid=0) at ./src/kdeinit/kinit.cpp:1323
#15 0x000055b4820010ff in main (argc=3, argv=<optimized out>) at ./src/kdeinit/kinit.cpp:1761
[Inferior 1 (process 27489) detached]