Background of the issue:
I cloned the website hidden link using WP All Migration and used the existing pages. I also imported the posts of the custom post types last week since there were many new ones since the cloning using WP All Import and WPML Import and Export. I am trying to change from German to Italian using the language switcher. The issue can be seen on this page: hidden link.
Symptoms:
I get an Error 500 when switching the language from German to Italian. Also, on pages like this one, when switching several times between German and French: hidden link.
Questions:
Why am I getting an Error 500 when switching languages?
How can I resolve the Error 500 when using the language switcher?
