Display default language post

I want to display posts of the default language if there is no post in the current language. I use WordPress 4.1 and Polylang 1.6.2. I tried everything what is described in the documentation https://polylang.wordpress.com/documentation/documentation-for-developers/tips-and-tricks/how-to-display-the-default-language-post-if-the-translation-does-not-exists/ but without success. Does the code in this description maybe not fit anymore to the current versions of WordPress and Polylang?

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