AJAX error: A fatal error occurred: Field moderation_state is unknown.

I'm currently using the latest alpha 6 version of scheduled updates and am also using the workbench moderation module on my site. I've added a scheduled updater field to my content type to target the moderation state. When editing the content type and trying to add a new scheduled update time, after hitting the submit button nothing happens. When inspecting the page I see an AJAX error: A fatal error occurred: Field moderation_state is unknown. I tried to repeating these steps on a fresh content type with no additional fields added other than the scheduled update field with the same results. I seem to get this same error no matter what type of field I'm targeting for the update as long as workbench moderation is enabled on the content type. If I disable workbench moderation it then allows me to schedule updates on fields but I need to target the moderation states specifically.