[Geschlossen] We are having trouble resetting WPML

Hintergrund des Themas:
Hello WPML Team,

I have the following issue on my website Europeaninternationalclub.com:

Some time ago, I set up WPML but later deactivated it. Since then, a lot has changed on the site (new subpages were added, the main language was changed, and some content was deleted). Now we would like to completely reinstall WPML from scratch, as if we had never used it before, because many errors occur when we try to reactivate it.

We attempted to reset WPML by removing the license key and deleting the plugin. Afterward, we reinstalled WPML and correctly set up the OTGS Installer. However, WPML was not in its default state after the reinstallation— all the old, faulty settings were still present. For example, when we try to change the main language, everything gets deleted, and other issues arise.

Our goal is to set up WPML entirely from scratch on our current website, without any previous history. Therefore, we need your assistance.

Thank you in advance for your help!

Die Symptome:

Fragen:
How can I reset WPML to its default state without any previous history?
Why do old settings persist after reinstalling WPML?