Step to reproduce : For small screens > enter the debug mode > go to the calendar app > access one of your meetings > access the tab "invitations" > try to change the state of attendance It's due to the missing kanban view used by the o2m field 'attendee_ids' We had to create this missing kanban view to allow theses actions on mobile. opw-2058770 closes odoo/odoo#36501 Signed-off-by: Adrien Dieudonné (adr) <adr@odoo.com>