[تم الحل] 404 error in Sub Categoty - seconday langauage

Background of the issue:
I am trying to access pages in the secondary language on my WordPress site using WPML, but they show a 404 error. The issue can be seen on this page: الرابط المخفي..*_ga*MjA5MTMxNjIwMy4xNzUyMDU4ODM2*_ga_12YF8XEEF0*czE3NTIwNTg4MzYkbzEkZzEkdDE3NTIwNTg4MzkkajU3JGwwJGgw*_ga_DYY59ZRPL3*czE3NTIwNTg4MzYkbzEkZzEkdDE3NTg4MzkkajU3JGwwJGgw*_ga_8Y133R6189*czE3NTIwNTg4MzYkbzEkZzEkdDE3NTIwNTg4MzkkajU3JGwwJGgw.

Symptoms:
Pages in the secondary language show a 404 error.

Questions:
Why do pages in the secondary language show a 404 error?