Crash - Inkscape 0.48.4 to OpenSCAD_converter

On 5 March 2016 I used the 'Ubuntu Software Center' to install inkscape on my Ubuntu 14.04 / Linux 3.13.0-79 system and tried to use it to convert a 2D drawing to 3D but got a crash as described below.

inkscape --version shows: Inkscape 0.48.4 r9939 (Jan 22 2014)

I then downloaded Inkscape_to_OpenSCAD_converter.zip from http://www.thingiverse.com/thing:24808 and unzipped it then unzipped paths2openscad-2.zip and copied paths2openscad.inx and paths2openscad.py into ~/.config/inkscape/extensions
after which ls -lgG shows:
total 32
-rwxr-xr-x 1 2550 Jun 15 2012 paths2openscad.inx
-rwxr-xr-x 1 26181 Jun 15 2012 paths2openscad.py

Then on a terminal screen I entered
    inkscape t1e.svg &

where t1e.svg is the following 6-line .svg file.

<?xml version="1.0" encoding="UTF-8"?>
<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="7mm" height="5mm" viewBox="0 0 7 5" version="1.1">
<g id="surface7">
<path style="fill:green;" d="M 3 3 v -1 h 2 v 1 Z "/>
</g>
</svg>

In inkscape I clicked View, Display Mode, Outline to see the green rectangle's outline path.

Then I clicked Extensions, Generate from Path, Paths to OpenSCAD...
at which point an error message box appeared, saying:
    Inkscape encountered an internal error and will close now.

and the following appeared on the terminal screen:

terminate called after throwing an instance of 'std::logic_error'
  what(): basic_string::_S_construct null not valid

Emergency save activated!
Emergency save completed. Inkscape will close now.
If you can reproduce this crash, please file a bug at www.inkscape.org
with a detailed description of the steps leading to the crash, so we can fix it.

Next, on a terminal screen I entered:
   gdb inkscape
and then
   run t1e.svg
and clicked stuff as before, with following output:

 Starting program: /usr/bin/inkscape t1e.svg
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[New Thread 0x7fffe754d700 (LWP 26782)]
[New Thread 0x7fffe6d4c700 (LWP 26783)]
[New Thread 0x7fffdd607700 (LWP 26784)]
[New Thread 0x7fffdce06700 (LWP 26785)]
[New Thread 0x7fffd3b86700 (LWP 26786)]
[Thread 0x7fffdce06700 (LWP 26785) exited]
[Thread 0x7fffd3b86700 (LWP 26786) exited]
terminate called after throwing an instance of 'std::logic_error'
  what(): basic_string::_S_construct null not valid

Program received signal SIGABRT, Aborted.
0x00007ffff07d3cc9 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
56 ../nptl/sysdeps/unix/sysv/linux/raise.c: No such file or directory.
(gdb) bt
#0 0x00007ffff07d3cc9 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
#1 0x00007ffff07d70d8 in __GI_abort () at abort.c:89
#2 0x00007ffff12fc535 in __gnu_cxx::__verbose_terminate_handler() () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#3 0x00007ffff12fa6d6 in ?? () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#4 0x00007ffff12fa703 in std::terminate() () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#5 0x00007ffff12fa922 in __cxa_throw () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#6 0x00007ffff134c1c7 in std::__throw_logic_error(char const*) () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#7 0x00007ffff13579f1 in char* std::string::_S_construct<char const*>(char const*, char const*, std::allocator<char> const&, std::forward_iterator_tag) () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#8 0x00007ffff1357d88 in std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(char const*, std::allocator<char> const&) () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#9 0x00007ffff6ec59ce in Glib::ustring::ustring(char const*) () from /usr/lib/x86_64-linux-gnu/libglibmm-2.4.so.1
#10 0x000000000077af44 in Inkscape::Extension::ParamDescription::get_widget(SPDocument*, Inkscape::XML::Node*, sigc::signal<void, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil>*) ()
#11 0x0000000000778ca9 in Inkscape::Extension::ParamNotebookPage::get_widget(SPDocument*, Inkscape::XML::Node*, sigc::signal<void, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil>*) ()
#12 0x0000000000779168 in Inkscape::Extension::ParamNotebook::get_widget(SPDocument*, Inkscape::XML::Node*, sigc::signal<void, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil>*) ()
#13 0x0000000000774cd7 in Inkscape::Extension::Extension::autogui(SPDocument*, Inkscape::XML::Node*, sigc::signal<void, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil, sigc::nil>*) ()
#14 0x0000000000acc431 in Inkscape::Extension::PrefDialog::PrefDialog(Glib::ustring, char const*, Gtk::Widget*, Inkscape::Extension::Effect*) ()
#15 0x0000000000783197 in Inkscape::Extension::Effect::prefs(Inkscape::UI::View::View*) ()
#16 0x00000000007c204c in sp_action_perform(SPAction*, void*) ()
#17 0x00007ffff49993b8 in g_closure_invoke () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#18 0x00007ffff49aad3d in ?? () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#19 0x00007ffff49b2a29 in g_signal_emit_valist () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#20 0x00007ffff49b2ce2 in g_signal_emit () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#21 0x00007fffe87fb390 in ?? () from /usr/lib/x86_64-linux-gnu/libunity-gtk2-parser.so.0
#22 0x00007ffff59cece7 in ?? () from /usr/lib/x86_64-linux-gnu/libgdk-x11-2.0.so.0
#23 0x00007ffff4426ce5 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
---Type <return> to continue, or q <return> to quit---
#24 0x00007ffff4427048 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#25 0x00007ffff442730a in g_main_loop_run () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#26 0x00007ffff5d8f447 in gtk_main () from /usr/lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0
#27 0x000000000062b6bc in sp_main_gui(int, char const**) ()
#28 0x000000000060f0df in main ()
(gdb)

Is there a way around this problem?

Note, some various system data follows (cut and paste from sysinfo)
Ubuntu 14.04 (trusty)
Gnome 3.8.4 (Ubuntu 2015-12-02)
Kernel 3.13.0-79-generic (#123-Ubuntu SMP Fri Feb 19 14:27:58 UTC 2016)
Intel(R) Core(TM) i3-2120 CPU @ 3.30GHz
15958 MiB 41% free