segfault when I click on any message in message list

[Allen Lowe]

here is the backtrace:
Program received signal SIGSEGV, Segmentation fault.
0x080a1e61 in postler_content_themed_style_sheet (self=0x8315060) at default/postler/postler-content.c:5843
5843 _tmp40_ = *((GdkColor*) _tmp39_);
(gdb) bt
#0 0x080a1e61 in postler_content_themed_style_sheet (self=0x8315060) at default/postler/postler-content.c:5843
#1 0x080a4126 in postler_content_real_clear (self=0x8315060) at default/postler/postler-content.c:6688
#2 0xb7e9e48c in g_cclosure_marshal_VOID__VOID () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#3 0xb7e80cc7 in ?? () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#4 0xb7e82372 in g_closure_invoke () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#5 0xb7e94e45 in ?? () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#6 0xb7e9db29 in g_signal_emit_valist () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#7 0xb7e9de3d in g_signal_emit_by_name () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#8 0x080772e6 in _lambda67_ (object=0x82d0068, pspec=0x81f5b40, _data9_=0x8145930) at default/postler/postler-bureau.c:3565
#9 0x080774dd in __lambda67__g_object_notify (_sender=0x82d0068, pspec=0x81f5b40, self=0x8145930) at default/postler/postler-bureau.c:3608
#10 0xb7e9ee48 in g_cclosure_marshal_VOID__PARAM () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#11 0xb7e82372 in g_closure_invoke () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#12 0xb7e95048 in ?? () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#13 0xb7e9db29 in g_signal_emit_valist () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#14 0xb7e9dcc2 in g_signal_emit () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#15 0xb7e840e1 in ?? () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#16 0xb7e833ef in ?? () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#17 0xb7e86379 in g_object_notify () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#18 0x080c7f0b in postler_messages_set_selected_message (self=0x82d0068, value=0x86eb588) at default/postler/postler-messages.c:4908
#19 0x080bc8aa in postler_messages_selection_changed (self=0x82d0068) at default/postler/postler-messages.c:582
#20 0x080be185 in _postler_messages_selection_changed_gtk_tree_selection_changed (_sender=0x81f5b90, self=0x82d0068) at default/postler/postler-messages.c:1219
#21 0xb7e9e48c in g_cclosure_marshal_VOID__VOID () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#22 0xb7e82372 in g_closure_invoke () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#23 0xb7e95048 in ?? () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#24 0xb7e9db29 in g_signal_emit_valist () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#25 0xb7e9dcc2 in g_signal_emit () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#26 0xb7c30f9c in ?? () from /usr/lib/libgtk-3.so.0
#27 0xb7c4862b in ?? () from /usr/lib/libgtk-3.so.0
#28 0xb7c4bd5e in ?? () from /usr/lib/libgtk-3.so.0
#29 0x080c6644 in postler_messages_real_button_press_event (base=0x82d0068, event=0x812fc68) at default/postler/postler-messages.c:4504
#30 0xb7b28034 in ?? () from /usr/lib/libgtk-3.so.0
#31 0xb7e80cc7 in ?? () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#32 0xb7e82372 in g_closure_invoke () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#33 0xb7e94e45 in ?? () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#34 0xb7e9d8d7 in g_signal_emit_valist () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#35 0xb7e9dcc2 in g_signal_emit () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#36 0xb7c66dbe in ?? () from /usr/lib/libgtk-3.so.0
#37 0xb7b277a8 in gtk_propagate_event () from /usr/lib/libgtk-3.so.0
#38 0xb7b27e27 in gtk_main_do_event () from /usr/lib/libgtk-3.so.0
#39 0xb79918fe in ?? () from /usr/lib/libgdk-3.so.0
#40 0xb79b83c8 in ?? () from /usr/lib/libgdk-3.so.0
#41 0xb7dccaa8 in g_main_context_dispatch () from /lib/i386-linux-gnu/libglib-2.0.so.0
#42 0xb7dcd270 in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#43 0xb7dcd92b in g_main_loop_run () from /lib/i386-linux-gnu/libglib-2.0.so.0
#44 0xb7b26e5d in gtk_main () from /usr/lib/libgtk-3.so.0
#45 0x080cbff3 in postler_reader_main (args=0xbffff3e4, args_length1=1) at default/postler/postler-reader.c:1678
#46 0x080cc0f1 in main (argc=1, argv=0xbffff3e4) at default/postler/postler-reader.c:1697