Hello,

I've move your message to a new topic, as not posted on the right place.

I need at least a link to the website to be able to check it.
But a screenshot of your module calendar options could help, as it could be an issue in settings, or a broken menu link.

If this happened after a Joomla 3 upgrade to Joomla 4, so maybe it's due to an issue i've found, and i will fix for 3.8.4, but you can fix this one by setting again the menu item for list of events (open menu link, edit it again to use the menu item type "list of events" and save the menu item).

Hope this helps ?

Best regards,
Cyril