WPML Translation Editor not showed, only the title of a page can be translatet

Hi

Today I bougt Betheme and WPML and installed it from scratch.

Now I stuck with the known problem (described on the WPML forum (Link: https://wpml.org/forums/topic/wpmls-translation-editor-only-display-the-title-of-the-page-not-the-content/)

I tryed the suggested solution several times without success.

(memory_limit 256 MB, newest version of Betheme and WPML)

Has anyone a hint how to solve this issue?

Kind regards

Martin