If a certain episode is embedded on other sites via the iframe code from the share menue the embedded player does NOT find the corresponding media files. Fehlende Medien Dateien
Die zur Verfügung gestellte Konfiguration ist fehlerhaft. Ohne Mediendateien kann der Player nichts abspielen.
The src string alone also raises the same error message.
But chance I came across another plugin in use that barely disabled al API calls. After enabling the ones for web player shortcode everything looks good so far.
I have found the solution to my problem and if, like me, you have found this forum looking for a solution, I would like to present it to you!
Because nothing is worse than always reading the answer “it works”, but never the solution itself!
Take a look at the THEME you are using. There in the directory under /wp-content/theme/… is a file named functions.php, search there for a part of the error text you get and deactivate this sub-function.
Try the internet search with this keywords: wordpress restx_logged_out error functions.php (for me, first german site helped me!)