Background of the issue:
I'm translating a custom post type using WPML. My site is in Dutch and English. I have 19 cases in Dutch, and they are translated and counted in English as well.
Symptoms:
When I check the posts within the translated language, I get a screen saying 'invalid posttype'.
Questions:
Why do I see an 'invalid posttype' error when checking translated posts?
Did I forget to translate the custom post type before translating the posts themselves? If yes, how do I fix this?