The problem being is that you are importing Bootstrap 2.x which comes shipped with Joomla (coming via <jdoc:include type="head" />
) and Bootstrap 3.3.5 via the following link:
https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js
which I assume you've manually added or is coming from the component.
You've also got the following jQuery snippet somewhere in the head which could be causing issues:
if ($('#ical_dialogJQ351').length) {
var bootstrap3_enabled = (typeof jQuery().emulateTransitionEnd == 'function');
if (bootstrap3_enabled && $('#ical_dialogJQ351').hasClass('hide')){
$('#ical_dialogJQ351').removeClass('hide');
}
//$('#ical_dialogJQ351').appendTo('body').modal({"backdrop":true,"keyboard":true,"show":true,"remote":""});
}
if ($('#action_dialogJQ351').length) {
var bootstrap3_enabled = (typeof jQuery().emulateTransitionEnd == 'function');
if (bootstrap3_enabled && $('#action_dialogJQ351').hasClass('hide')){
$('#action_dialogJQ351').removeClass('hide');
}
//$('#action_dialogJQ351').appendTo('body').modal({"backdrop":true,"keyboard":true,"show":true,"remote":""});
}