Background of the issue:
I am developing a site using WPML and encountering an issue when purchasing products in the main language, Serbian. The site is under development, and the error occurs only in the main language. The error appears in the console when trying to buy a product on the store. The error message is: jquery.min.js?ver=3.7.1:2 POST 隐藏链接 500 (Internal Server Error). The issue does not occur in other languages. The problem can be observed on this link: 隐藏链接. The language switcher is in the footer.
Symptoms:
500 Internal Server Error when purchasing products in the main language (Serbian) on the site.
Questions:
Why does the 500 error occur only in the main language?
How can I resolve the 500 error when purchasing products in Serbian?
