[Closed] Impossible to delete all translations

Background of the issue:
I am trying to delete all translations by following this guide: https://wpml.org/documentation/getting-started-guide/language-setup/deleting-languages-and-plugin-data-by-doing-a-wpml-reset-on-your-site/. The issue can be seen on this page: hidden link.

Symptoms:
When I click on the button "Yes, delete all "anglais" translations", it loads for a long time and at the end I get back to the same popup with the same button. The translations were not deleted.

Questions:
Why are the translations not being deleted after clicking the button?
Is there a way to resolve the issue of the page reloading without deleting translations?