Still happens for me on Ubuntu 17.04 on my Dell XPS13:

max@xps13:~$ webbrowser-app 

(webbrowser-app:4031): Gtk-WARNING **: Failed to parse /etc/gtk-3.0/settings.ini: Keine Berechtigung
libGL error: MESA-LOADER: failed to retrieve device information
libGL error: Version 4 or later of flush extension not found
libGL error: failed to load driver: i915
libGL error: MESA-LOADER: failed to retrieve device information
inotify_add_watch("/home/max/.config/ubuntu-ui-toolkit/theme.ini") failed: "No such file or directory"
UCUriHandler: Empty "APP_ID" environment variable, ignoring.
qml: webbrowser-app using oxide 1.21.5 (chromium 57.0.2987.110)
unity::action::ActionManager::ActionManager(QObject*):
	Could not determine application identifier. HUD will not work properly.
	Provide your application identifier in $APP_ID environment variable.
libGL error: MESA-LOADER: failed to retrieve device information
libGL error: Version 4 or later of flush extension not found
libGL error: failed to load driver: i915
libGL error: MESA-LOADER: failed to retrieve device information

(webbrowser-app:4031): dconf-CRITICAL **: unable to create file '/run/user/1001/dconf/user': Keine Berechtigung.  dconf will not work properly.

(webbrowser-app:4031): dconf-CRITICAL **: unable to create file '/run/user/1001/dconf/user': Keine Berechtigung.  dconf will not work properly.

(webbrowser-app:4031): dconf-CRITICAL **: unable to create file '/run/user/1001/dconf/user': Keine Berechtigung.  dconf will not work properly.

(webbrowser-app:4031): dconf-CRITICAL **: unable to create file '/run/user/1001/dconf/user': Keine Berechtigung.  dconf will not work properly.

(webbrowser-app:4031): dconf-CRITICAL **: unable to create file '/run/user/1001/dconf/user': Keine Berechtigung.  dconf will not work properly.

(webbrowser-app:4031): dconf-CRITICAL **: unable to create file '/run/user/1001/dconf/user': Keine Berechtigung.  dconf will not work properly.

(webbrowser-app:4031): dconf-CRITICAL **: unable to create file '/run/user/1001/dconf/user': Keine Berechtigung.  dconf will not work properly.

(webbrowser-app:4031): dconf-CRITICAL **: unable to create file '/run/user/1001/dconf/user': Keine Berechtigung.  dconf will not work properly.

(webbrowser-app:4031): dconf-CRITICAL **: unable to create file '/run/user/1001/dconf/user': Keine Berechtigung.  dconf will not work properly.

(webbrowser-app:4031): dconf-CRITICAL **: unable to create file '/run/user/1001/dconf/user': Keine Berechtigung.  dconf will not work properly.

(webbrowser-app:4031): dconf-CRITICAL **: unable to create file '/run/user/1001/dconf/user': Keine Berechtigung.  dconf will not work properly.

(webbrowser-app:4031): dconf-CRITICAL **: unable to create file '/run/user/1001/dconf/user': Keine Berechtigung.  dconf will not work properly.

(webbrowser-app:4031): dconf-CRITICAL **: unable to create file '/run/user/1001/dconf/user': Keine Berechtigung.  dconf will not work properly.
[0803/014332.722002:ERROR:child_thread_impl.cc(762)] Request for unknown Channel-associated interface: ui::mojom::GpuMain
error calling result "An AppArmor policy prevents this sender from sending this message to this recipient; type=\"method_call\", sender=\":1.129\" (uid=1001 pid=4031 comm=\"webbrowser-app \") interface=\"com.canonical.libertine.Service.Operations\" member=\"list\" error name=\"(unset)\" requested_reply=\"0\" destination=\"com.canonical.libertine.Service\" (uid=1001 pid=2059 comm=\"/usr/bin/python3 /usr/bin/libertined --cache-outpu\")"
error calling result "An AppArmor policy prevents this sender from sending this message to this recipient; type=\"method_call\", sender=\":1.129\" (uid=1001 pid=4031 comm=\"webbrowser-app \") interface=\"com.canonical.libertine.Service.OperationsMonitor\" member=\"running\" error name=\"(unset)\" requested_reply=\"0\" destination=\"com.canonical.libertine.Service\" (uid=1001 pid=2059 comm=\"/usr/bin/python3 /usr/bin/libertined --cache-outpu\")"
lastError - no arguments?
error calling result "An AppArmor policy prevents this sender from sending this message to this recipient; type=\"method_call\", sender=\":1.129\" (uid=1001 pid=4031 comm=\"webbrowser-app \") interface=\"com.canonical.libertine.Service.OperationsMonitor\" member=\"last_error\" error name=\"(unset)\" requested_reply=\"0\" destination=\"com.canonical.libertine.Service\" (uid=1001 pid=2059 comm=\"/usr/bin/python3 /usr/bin/libertined --cache-outpu\")"
lastError - no arguments?
error calling result "An AppArmor policy prevents this sender from sending this message to this recipient; type=\"method_call\", sender=\":1.129\" (uid=1001 pid=4031 comm=\"webbrowser-app \") interface=\"com.canonical.libertine.Service.OperationsMonitor\" member=\"result\" error name=\"(unset)\" requested_reply=\"0\" destination=\"com.canonical.libertine.Service\" (uid=1001 pid=2059 comm=\"/usr/bin/python3 /usr/bin/libertined --cache-outpu\")"
lastError - no arguments?
APP_ID isn't set, the handler can not be registered
QOpenGLShader: could not create shader

(webbrowser-app:4031): dconf-CRITICAL **: unable to create file '/run/user/1001/dconf/user': Keine Berechtigung.  dconf will not work properly.
QOpenGLShader: could not create shader
QOpenGLShader: could not create shader
QOpenGLShader: could not create shader
QOpenGLShader: could not create shader
QOpenGLShader: could not create shader
APP_ID isn't set, the handler ignored
qml: Loaded 18 UA override(s) from file:///usr/lib/x86_64-linux-gnu/qt5/qml/Ubuntu/Web/ua-overrides-desktop.js
QOpenGLShader: could not create shader
QOpenGLShader: could not create shader
intel_do_flush_locked failed: Eingabe-/Ausgabefehler
[0803/014447.975041:FATAL:oxide_browser_process_main.cc(472)] Check failed: state_ == STATE_NOT_STARTED || state_ == STATE_SHUTDOWN. BrowserProcessMain::Shutdown() should be called before process exit
#0 0x7f4b5ae4532e <unknown>
#1 0x7f4b5ae5fd8e <unknown>
#2 0x7f4b5c4960d9 <unknown>
#3 0x7f4b8dc75270 <unknown>
#4 0x7f4b8dc752ca exit
#5 0x7f4b7466b16e <unknown>
#6 0x7f4b7467111c <unknown>
#7 0x7f4b746712f5 <unknown>
#8 0x7f4b74676abb <unknown>
#9 0x7f4b744283fc <unknown>
#10 0x7f4b74428660 <unknown>
#11 0x7f4b7467726c <unknown>
#12 0x7f4b74416e63 <unknown>
#13 0x7f4b74418fe0 <unknown>
#14 0x7f4b90b10d6b QSGPlainTexture::bind()
#15 0x7f4b90c4dc07 <unknown>
#16 0x7f4b90af6682 QSGBatchRenderer::Renderer::renderMergedBatch()
#17 0x7f4b90af7bc5 QSGBatchRenderer::Renderer::renderBatches()
#18 0x7f4b90afd2b5 QSGBatchRenderer::Renderer::render()
#19 0x7f4b90b08bdf QSGRenderer::renderScene()
#20 0x7f4b90b092ab QSGRenderer::renderScene()
#21 0x7f4b90b18f3e QSGRenderContext::renderNextFrame()
#22 0x7f4b90b627fe QQuickWindowPrivate::renderSceneGraph()
#23 0x7f4b90b2fa35 <unknown>
#24 0x7f4b90b6d2a6 QQuickWindow::event()
#25 0x7f4b8f94e35c QApplicationPrivate::notify_helper()
#26 0x7f4b8f955b11 QApplication::notify()
#27 0x7f4b8e81d8a0 QCoreApplication::notifyInternal2()
#28 0x7f4b8f1c621e QWindowPrivate::deliverUpdateRequest()
#29 0x7f4b8f1c6769 QWindow::event()
#30 0x7f4b90b6d245 QQuickWindow::event()
#31 0x7f4b8f94e35c QApplicationPrivate::notify_helper()
#32 0x7f4b8f955b11 QApplication::notify()
#33 0x7f4b8e81d8a0 QCoreApplication::notifyInternal2()
#34 0x7f4b8e870eae QTimerInfoList::activateTimers()
#35 0x7f4b8e8713d1 <unknown>
#36 0x7f4b8ba35377 g_main_context_dispatch
#37 0x7f4b8ba355e0 <unknown>
#38 0x7f4b8ba3568c g_main_context_iteration
#39 0x7f4b8e871f0f QEventDispatcherGlib::processEvents()
#40 0x7f4b8e81b88a QEventLoop::exec()
#41 0x7f4b8e823ffc QCoreApplication::exec()
#42 0x556b21066b45 (/usr/bin/webbrowser-app+0x556b21066b44)
#43 0x7f4b8dc5b3f1 __libc_start_main
#44 0x556b21066caa (/usr/bin/webbrowser-app+0x556b21066ca9)

^C^CAbgebrochen (Speicherabzug geschrieben)
max@xps13:~$ 


"Keine Berechtigung" is "No permission", "Abgebrochen (Speicherabzug geschrieben)" is "Canceled (Memory-dump written)"

I'm using the Mesa PPA by joe-yasi.