[Fermé] Blog posts not translatable (Error message)

Background of the issue:
I am trying to translate my blog posts using WPML, but I keep encountering issues. The problem can be seen on this page: lien caché.

Symptoms:
I receive error messages indicating critical errors or that the post was already translated. I expected the Advanced translator to open for translating my post, but instead, I got an error message.

Questions:
Why am I receiving error messages when trying to translate my blog posts?
Why does it say the post was already translated when it wasn't?