OtterBrowser/otter-browser: crash when saving files

gdb_backtrace.txt

#0  0x00007f07c076b528 in raise () from /usr/lib/libc.so.6
#1  0x00007f07c076c93a in abort () from /usr/lib/libc.so.6
#2  0x00007f07c07a9bb2 in __libc_message () from /usr/lib/libc.so.6
#3  0x00007f07c07af0fe in malloc_printerr () from /usr/lib/libc.so.6
#4  0x00007f07c07af8db in _int_free () from /usr/lib/libc.so.6
#5  0x00007f07c1652ed0 in QObject::event(QEvent*) () from /usr/lib/libQt5Core.so.5
#6  0x00007f07c4d5c00c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/libQt5Widgets.so.5
#7  0x00007f07c4d614e6 in QApplication::notify(QObject*, QEvent*) () from /usr/lib/libQt5Widgets.so.5
#8  0x00007f07c162389b in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/libQt5Core.so.5
#9  0x00007f07c1625c96 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /usr/lib/libQt5Core.so.5
#10 0x00007f07c1679e33 in ?? () from /usr/lib/libQt5Core.so.5
#11 0x00007f07bf6b19fd in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#12 0x00007f07bf6b1ce0 in ?? () from /usr/lib/libglib-2.0.so.0
#13 0x00007f07bf6b1d8c in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#14 0x00007f07c167a23f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#15 0x00007f07c162126a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQt5Core.so.5
#16 0x00007f07c4f56bbd in QDialog::exec() () from /usr/lib/libQt5Widgets.so.5
#17 0x0000000000522ff0 in Otter::TransfersManager::getSavePath(QString const&, QString) ()
#18 0x000000000051e058 in Otter::Transfer::start(QNetworkReply*, QString const&, bool, bool) ()
#19 0x000000000051fbe4 in Otter::Transfer::Transfer(QNetworkReply*, QString const&, bool, bool, QObject*) ()
#20 0x0000000000523d2f in Otter::TransfersManager::startTransfer(QUrl const&, QString const&, bool, bool) ()
#21 0x00007ffd6170e180 in ?? ()
#22 0x00000000070395c0 in ?? ()
#23 0x0000000000000068 in ?? ()
#24 0x0000000000000011 in ?? ()
#25 0x00007ffd6170e300 in ?? ()
#26 0x0000000000617b02 in Otter::QtWebKitWebWidget::optionChanged(QString const&, QVariant const&) ()
#27 0x00007ffd6170e270 in ?? ()
#28 0x00000013c16d6de0 in ?? ()
#29 0x0000000003491240 in ?? ()
#30 0x00007f07c66e87c0 in ?? ()
#31 0x0000000003499460 in ?? ()
#32 0x0000000000000015 in ?? ()
#33 0x0000000000000010 in ?? ()
#34 0x00007f07c1a74418 in ?? () from /usr/lib/libQt5Core.so.5
#35 0x0000000000694c40 in ?? ()
#36 0x0000000000000000 in ?? ()