Bug : Uncaught TypeError: Failed to execute 'observe' on 'MutationObserver': parameter 1 is not of type 'Node'.

[jerome-renaud]

Contexte
https://intra.epitech.eu/module/2019/G-JAM-001/TLS-0-2/registered
Trace de la pile
scripts/activity.js:26 (fonction anonyme)
`(() => {
if (document.location.href.endsWith('/registered')) {
console.log("Intra refined Setup: ACTIVITY");

    const list_inscrit_table = document.getElementById('list-inscrit');
    let button = null
    function upsertTeamsButton() {
        const buttons_container = Array.from(document.getElementsByClassName('admin')).find((e, id) => id === 0);
        if (!buttons_container) return;
        const students = Array.from(list_inscrit_table.getElementsByTagName('td')).filter((e) => e.dataset.login).map((e) => e.dataset.login)
        if (students.length === 0) return;
        if (button !== null) {
            buttons_container.removeChild(button)
        }
        button = createButtonTeams(students)
        buttons_container.appendChild(button)
    }

    // Create an observer instance linked to the callback function
    const observer = new MutationObserver((mutationsList, observer) => {
        upsertTeamsButton();
    });

    // Start observing the target node for configured mutations
    upsertTeamsButton();
   observer.observe(list_inscrit_table, { childList: true, subtree: true }); // <--- ici
    //*/
}

})();`