Stacktrace
------------------
#0  Notification::parseNetworkPackage (this=this@entry=0x0, np=...)
    at /workspace/build/plugins/notifications/notification.cpp:177
#1  0x00007fffd37cc471 in Notification::update (this=this@entry=0x0, np=...)
    at /workspace/build/plugins/notifications/notification.cpp:79
#2  0x00007fffd37d2256 in NotificationsDbusInterface::processPackage (
    this=0x7e8000, np=...)
    at /workspace/build/plugins/notifications/notificationsdbusinterface.cpp:96
#3  0x00007fffd37ccc7d in NotificationsPlugin::receivePackage (this=0x7e7dd0, 
    np=...)
    at /workspace/build/plugins/notifications/notificationsplugin.cpp:59
#4  0x00007ffff7bbd538 in Device::privateReceivedPackage (
    this=<optimized out>, np=...) at /workspace/build/core/device.cpp:345
#5  0x00007ffff5d757b6 in QtPrivate::QSlotObjectBase::call (a=0x7fffffffbd10, 
    r=0x767a30, this=<optimized out>)
    at ../../include/QtCore/../../src/corelib/kernel/qobjectdefs_impl.h:378
#6  QMetaObject::activate (sender=sender@entry=0x7afd70, 
    signalOffset=<optimized out>, 
    local_signal_index=local_signal_index@entry=4, 
    argv=argv@entry=0x7fffffffbd10) at kernel/qobject.cpp:3749
#7  0x00007ffff5d75d97 in QMetaObject::activate (
    sender=sender@entry=0x7afd70, 
    m=m@entry=0x7ffff7dd5ac0 <DeviceLink::staticMetaObject>, 
    local_signal_index=local_signal_index@entry=4, 
    argv=argv@entry=0x7fffffffbd10) at kernel/qobject.cpp:3628
#8  0x00007ffff7bc3ec5 in DeviceLink::receivedPackage (
    this=this@entry=0x7afd70, _t1=...)
    at /workspace/build/obj-x86_64-linux-gnu/core/moc_devicelink.cpp:209
#9  0x00007ffff7ba0b32 in LanDeviceLink::dataReceived (this=0x7afd70)
    at /workspace/build/core/backends/lan/landevicelink.cpp:133
#10 0x00007ffff5d757b6 in QtPrivate::QSlotObjectBase::call (a=0x7fffffffbed0, 
    r=0x7afd70, this=<optimized out>)
    at ../../include/QtCore/../../src/corelib/kernel/qobjectdefs_impl.h:378
#11 QMetaObject::activate (sender=sender@entry=0x7dcb80, 
    signalOffset=<optimized out>,
    local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x0)
    at kernel/qobject.cpp:3749
#12 0x00007ffff5d75d97 in QMetaObject::activate (
    sender=sender@entry=0x7dcb80, 
    m=m@entry=0x7ffff7dd5980 <SocketLineReader::staticMetaObject>, 
    local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x0)
    at kernel/qobject.cpp:3628
#13 0x00007ffff7bc4150 in SocketLineReader::readyRead (
    this=this@entry=0x7dcb80)
    at /workspace/build/obj-x86_64-linux-gnu/core/moc_socketlinereader.cpp:134
#14 0x00007ffff7ba5ae6 in SocketLineReader::dataReceived (this=0x7dcb80)
    at /workspace/build/core/backends/lan/socketlinereader.cpp:51
#15 0x00007ffff5d757b6 in QtPrivate::QSlotObjectBase::call (a=0x7fffffffc020, 
    r=0x7dcb80, this=<optimized out>)
    at ../../include/QtCore/../../src/corelib/kernel/qobjectdefs_impl.h:378
#16 QMetaObject::activate (sender=0xe99040, signalOffset=<optimized out>, 
    local_signal_index=<optimized out>, argv=<optimized out>)
    at kernel/qobject.cpp:3749
#17 0x00007ffff510fb07 in ?? ()
   from /usr/lib/x86_64-linux-gnu/libQt5Network.so.5
#18 0x00007ffff50f39e1 in ?? ()
   from /usr/lib/x86_64-linux-gnu/libQt5Network.so.5
#19 0x00007ffff5d75489 in QMetaObject::activate (sender=0x81a4e0, 
    signalOffset=<optimized out>, local_signal_index=<optimized out>, 
    argv=<optimized out>) at kernel/qobject.cpp:3766
#20 0x00007ffff50c1773 in ?? ()
   from /usr/lib/x86_64-linux-gnu/libQt5Network.so.5
#21 0x00007ffff50c182c in ?? ()
   from /usr/lib/x86_64-linux-gnu/libQt5Network.so.5
#22 0x00007ffff50d20e1 in ?? ()
   from /usr/lib/x86_64-linux-gnu/libQt5Network.so.5
#23 0x00007ffff6a88acc in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#24 0x00007ffff6a90417 in QApplication::notify(QObject*, QEvent*) ()
   from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#25 0x00007ffff5d483c8 in QCoreApplication::notifyInternal2 (
    receiver=0x79fa90, event=event@entry=0x7fffffffd4e0)
    at kernel/qcoreapplication.cpp:1044
#26 0x00007ffff5da022d in QCoreApplication::sendEvent (event=0x7fffffffd4e0, 
    receiver=<optimized out>)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:234
#27 socketNotifierSourceDispatch (source=0x6cccd0)
    at kernel/qeventdispatcher_glib.cpp:106
#28 0x00007fffeffbb197 in g_main_context_dispatch ()
   from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#29 0x00007fffeffbb3f0 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#30 0x00007fffeffbb49c in g_main_context_iteration ()
   from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#31 0x00007ffff5d9f5af in QEventDispatcherGlib::processEvents (this=0x6a3350, 
    flags=...) at kernel/qeventdispatcher_glib.cpp:423
#32 0x00007fffe6fc51a1 in ?? ()
   from /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5
#33 0x00007ffff5d4664a in QEventLoop::exec (this=this@entry=0x7fffffffd720, 
    flags=..., flags@entry=...) at kernel/qeventloop.cpp:212
#34 0x00007ffff5d4f854 in QCoreApplication::exec ()
    at kernel/qcoreapplication.cpp:1332
#35 0x0000000000401dd4 in main (argc=1, argv=<optimized out>)
    at /workspace/build/daemon/kdeconnectd.cpp:88

Additional Information
----------------------
My devices previously shares the same Android ID, which makes KDE Connect unhappy so I replaces one and deleted ~/.config/kdeconnect.

OS: KDE neon User Edition 5.12
Version: 1.2.1-0neon+16.04+xenial+build31
Locale: zh_TW.UTF-8