Hi Lucas and sorry to bother you again, I have a new issue on the website. As you know, the Frithjof Schuon Archive website is quite compley and is in three languages. I am now working on the post types Books. I have 118 posts for each language in this category and all had been translated in the three languages. English should be the primary language of the site but some posts have been translated from german or french to english. Is there a way to reassign the original language "English" to the posts? This should be done for all post types. Can you help me with this? Also, I wanted to leave you a five-star review on WordPress but the link you sent led me to a WPML+WooCommerce Plugin so I was not sure what to do since I am not using this plugin. Thanks for your help again...
The short answer is yes, but only if the post is not translated into all other languages. I checked your website, and since all books are translated into all languages, you can't change the language anymore.
Check here: hidden link
That shouldn't be an issue, though. The default language you choose for the website, does not necessarily need to match the language in which the post was created in. You can create content in any language you have on the website.
Thank you so much for your clarification and for the video. I am trying to get this complex website to work properly again and that is the reason for my question. If you go up and look at this page hidden link you will see that there are some breadcrumbs and that there is a php error showing and the breadcrumbs are not showing correctly (the title shows up twice and the separators are also showing up strangely. I thought this might be because there is confusion about which is the original language. I tried to add a sentence to the original language post (german) to see whether the translated contents are lost or whether I can continue to work on these translations. WPML suggests I switch to the advanced editor, which I would like to do, but I am worried about losing content. I hope I have been clear on what I would like to do... Let me know as it is difficult to explain properly.
To remove the error messages from the front end, you can add this to your wp-config.php:
// Disable display of errors and warnings
define( 'WP_DEBUG_DISPLAY', false );
@ini_set( 'display_errors', 0 );
Make sure that this is not already there, or you'll get errors. Ensure to have a backup.
Furthermore, in this case, I recommend you to create a staging version to make the proper tests, this way you don't need to worry about breaking the live website. Deactivate WPML on staging, and check if the issue persists. Let me know.