[mdl] Site does not build

On trying to build the site I get this error:

(.venv) [masin@selena posts]$ nikola build
Scanning posts........done!
.  render_galleries:output/galleries
.  render_galleries:output/galleries/demo
.  render_galleries:output/galleries/index.html
TaskError - taskid:render_galleries:output/galleries/index.html
PythonAction Error
Traceback (most recent call last):
  File "/home/masin/Dokumente/blog.wiedner.berlin/.venv/lib/python3.11/site-packages/doit/action.py", line 461, in execute
    returned_value = self.py_callable(*self.args, **kwargs)
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/masin/Dokumente/blog.wiedner.berlin/.venv/lib/python3.11/site-packages/nikola/plugins/task/galleries.py", line 717, in render_gallery_index
    self.site.render_template(template_name, output_name, context)
  File "/home/masin/Dokumente/blog.wiedner.berlin/.venv/lib/python3.11/site-packages/nikola/nikola.py", line 1491, in render_template
    data = self.template_system.render_template(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/masin/Dokumente/blog.wiedner.berlin/.venv/lib/python3.11/site-packages/nikola/plugins/template/mako.py", line 118, in render_template
    data = template.render_unicode(**context)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/masin/Dokumente/blog.wiedner.berlin/.venv/lib/python3.11/site-packages/mako/template.py", line 444, in render_unicode
    return runtime._render(
           ^^^^^^^^^^^^^^^^
  File "/home/masin/Dokumente/blog.wiedner.berlin/.venv/lib/python3.11/site-packages/mako/runtime.py", line 874, in _render
    _render_context(
  File "/home/masin/Dokumente/blog.wiedner.berlin/.venv/lib/python3.11/site-packages/mako/runtime.py", line 916, in _render_context
    _exec_template(inherit, lclcontext, args=args, kwargs=kwargs)
  File "/home/masin/Dokumente/blog.wiedner.berlin/.venv/lib/python3.11/site-packages/mako/runtime.py", line 943, in _exec_template
    callable_(context, *args, **kwargs)
  File "/home/masin/Dokumente/blog.wiedner.berlin/staging/cache/.mako.tmp/base.tmpl.py", line 101, in render_body
    __M_writer(str(base.late_load_js()))
                   ^^^^^^^^^^^^^^^^^^^
  File "/home/masin/Dokumente/blog.wiedner.berlin/staging/cache/.mako.tmp/base_helper.tmpl.py", line 401, in render_late_load_js
    if colorbox_locales[lang]:
       ~~~~~~~~~~~~~~~~^^^^^^
TypeError: 'Undefined' object is not subscriptable

Building upon the default conf.pyI just set:

THEME = "mdl"
GLOBAL_CONTEXT.update({
    "mdl__version": "1.3.0",
    "mdl__color_scheme": "indigo-pink",
    "mdl__roboto_font": False,
    "mdl__late_load_css": False,
    "mdl__cachebusting": "1",
    "mdl__fixed_header": False,
    "mdl__fixed_drawer": False,
    "mdl__no_drawer_button": False,
    "mdl__no_desktop_drawer_button": False,
    "mdl__multiple_header": False,
    "mdl__header_scroll": False,
    "mdl__header_waterfall": False,
    "mdl__header_waterfall_hide_top": False,
    "mdl__header_transparent": False,
    "mdl__header_seamed": False,
    "mdl__footer": "",
    "mdl__navigation_large_screen_only": False,
    "mdl__drawer_small_screen_only": False,
    "mdl__custom_css": False,
    "mdl__custom_js": False,
    "drawer_title": "",
    "drawer_logo_url": "",
    "drawer_show_title": "",
    "drawer_description": "",
    "drawer_note": "",
    "title_row_middle": False,
    "navigation_row_middle": False,
    "breadcrumb_separator": ">",
    "post_type": {
        "text": "format_align_justify",
    },
    "top_nav_header": False,
    "more_button_header": [
        ("/pages/handbook.html", "Handbook", "Handbook"),
    ],
    "image_plugin": "colorbox",
})

Version info:

(.venv) [masin@selena posts]$ nikola --version
Nikola v8.2.4

getnikola / nikola-themes

[mdl] Site does not build #216