To help you debug, here is the output of running the command otter-browser with GNU's debugger:
~$ gdb otter-browser
GNU gdb (Ubuntu 7.7.1-0ubuntu5~14.04.3) 7.7.1
Copyright (C) 2014 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/>.
For help, type "help".
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Reading symbols from otter-browser...(no debugging symbols found)...done.
(gdb) run
Starting program: /usr/bin/otter-browser
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[New Thread 0x7fffe38fa700 (LWP 32207)]
[New Thread 0x7fffdab67700 (LWP 32208)]
[New Thread 0x7fffda366700 (LWP 32209)]
[New Thread 0x7fffd10de700 (LWP 32211)]
[New Thread 0x7fffd08dd700 (LWP 32212)]
[New Thread 0x7fffc7fff700 (LWP 32213)]
[New Thread 0x7fffc77fe700 (LWP 32214)]
[Thread 0x7fffd08dd700 (LWP 32212) exited]
[New Thread 0x7fffd08dd700 (LWP 32215)]
[New Thread 0x7fff6c33d700 (LWP 32216)]
[New Thread 0x7fff6b2bb700 (LWP 32217)]
[New Thread 0x7fff6a6ba700 (LWP 32218)]
[New Thread 0x7fff69e39700 (LWP 32220)]
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff4fc2d42 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5WebKit.so.5
(gdb) backtrace
#0 0x00007ffff4fc2d42 in ?? ()
from /usr/lib/x86_64-linux-gnu/libQt5WebKit.so.5
#1 0x00007ffff40dc072 in QWebHitTestResultPrivate::QWebHitTestResultPrivate(WebCore::HitTestResult const&) () from /usr/lib/x86_64-linux-gnu/libQt5WebKit.so.5
#2 0x00007ffff40dc550 in QWebFrameAdapter::hitTestContent(QPoint const&) const
() from /usr/lib/x86_64-linux-gnu/libQt5WebKit.so.5
#3 0x00007ffff3a3af50 in QWebFrame::hitTestContent(QPoint const&) const ()
from /usr/lib/x86_64-linux-gnu/libQt5WebKitWidgets.so.5
#4 0x00007ffff3a3ee08 in QWebPage::frameAt(QPoint const&) const ()
from /usr/lib/x86_64-linux-gnu/libQt5WebKitWidgets.so.5
#5 0x0000000000725ba3 in Otter::QtWebKitWebWidget::getHitTestResult(QPoint const&) ()
#6 0x0000000000684802 in Otter::WebWidget::handleToolTipEvent(QHelpEvent*, QWidget*) ()
#7 0x000000000072a2ff in Otter::QtWebKitWebWidget::eventFilter(QObject*, QEvent*) ()
#8 0x00007ffff771ce53 in QCoreApplicationPrivate::sendThroughObjectEventFilters(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#9 0x00007ffff332bc6c in QApplicationPrivate::notify_helper(QObject*, QEvent*)
() from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#10 0x00007ffff3332770 in QApplication::notify(QObject*, QEvent*) ()
from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#11 0x00007ffff771cc2d in QCoreApplication::notifyInternal(QObject*, QEvent*)
---Type <return> to continue, or q <return> to quit---
() from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#12 0x00007ffff332ebef in QApplication::event(QEvent*) ()
from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#13 0x00007ffff332bc8c in QApplicationPrivate::notify_helper(QObject*, QEvent*)
() from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#14 0x00007ffff3330e56 in QApplication::notify(QObject*, QEvent*) ()
from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#15 0x00007ffff771cc2d in QCoreApplication::notifyInternal(QObject*, QEvent*)
() from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#16 0x00007ffff77691ad in QTimerInfoList::activateTimers() ()
from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#17 0x00007ffff7769661 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#18 0x00007ffff0d52e04 in g_main_context_dispatch ()
from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#19 0x00007ffff0d53048 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#20 0x00007ffff0d530ec in g_main_context_iteration ()
from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#21 0x00007ffff77699ab in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#22 0x00007ffff771b96b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#23 0x00007ffff77220e1 in QCoreApplication::exec() ()
from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
---Type <return> to continue, or q <return> to quit---
#24 0x0000000000542b03 in main ()
(gdb)
If there is a better place to send a bug report, please let me know. Thanks.