undefined index 'type' in plex_theme_hook_context() after updating core and several modules

I'm receiving the following error (after rebuilding the theme registry) repeated about 800 times after updating core and several modules on an existing site;

Notice: Undefined index: type in plex_theme_hook_context() (line 209 of /var/www/sites/all/themes/hexagon/HexagonBase/plugins/plex-theme/theme_registry.build.inc).

The theme appears to not be working in several places as well due to missing information;

Notice: Undefined variable: directory in include() (line 29 of /var/www/sites/all/themes/mytheme/overrides/page.vars.inc).
Notice: Undefined variable: site_name in include() (line 33 of /var/www/sites/all/themes/mytheme/overrides/page.vars.inc).
Notice: Undefined variable: site_name in include() (line 38 of /var/www/sites/all/themes/mytheme/overrides/page.vars.inc).
Notice: Undefined variable: site_name in include() (line 43 of /var/www/sites/all/themes/mytheme/overrides/page.vars.inc).
Notice: Undefined variable: main_menu in include() (line 52 of /var/www/sites/all/themes/mytheme/overrides/page.vars.inc).
Notice: Undefined variable: secondary_menu in include() (line 60 of /var/www/sites/all/themes/mytheme/overrides/page.vars.inc).

page.vars.inc is attached.

My assumption is that something in core changed in how the theme registry is processed and due to hexagon's advanced registry building process something broke. This is just a guess though. Any advice on how to proceed to find the source and resolution of the bug would be greatly appreciated.