Resolved
Reported for: WPML Multilingual CMS 4.5.8
Resolved in: WPML 4.6.5
Overview of the issue
This problem happens only if you try to translate a page from the “edit” page of the WordPress native interface and you also use the Cornerstone page builder or Themeco’s PRO theme on those pages.
Workaround
Update WPML to version 4.6.5