I just migrated my site from Joomla 2.5 to 3.9.I updated JEvents from 3.2.1 to 3.6.4.
Editing an event in the backend no longer works: see attached file

There is an error message :
YSTS_SYSTEM_MESSAGES
You are editing an existing event.
JevStdRequiredFields.fields.push({'name':'title', 'default' :'' ,'reqmsg':'Veuillez ajouter le champ obligatoire : Titre'}); Joomla.submitbutton = function (pressbutton) { if (pressbutton.substr(0, 6) == 'cancel' || !(pressbutton == 'icalevent.save' || pressbutton == 'icalrepeat.save' || pressbutton == 'icalevent.savenew' || pressbutton == 'icalrepeat.savenew' || pressbutton == 'icalevent.apply' || pressbutton == 'icalrepeat.apply')) { if (document.adminForm['catid']) { // restore catid to input value document.adminForm['catid'].value = 0; document.adminForm['catid'].disabled = true; } Joomla.submitform(pressbutton); return; } var form = document.adminForm; var editorElement = jevjq('#jevcontent'); if (editorElement.length) {


Thank You