Out of the box ES_ReindexAll method for Enterprise Search appears to be broken

If I hit "Reindex all" either from the User Menu or from the more button on an Indexed configuration item, I get the following error:

"String was not recognized as a valid DateTime"

It looks like some string should be converted to a date, but is formatted incorrectly. I'm no programmer, but I worked out that it is using the ES_ReindexAll method. I'd be really grateful if a Java expert on the forum could have a look at the method copied below and work out if there is something I could easily correct!

Running Standard demo system, 12.0 SP11 Build 26239

Thank you!

Tim

============= ES_ReindexAll method ===================

require([
    'ES/Scripts/Classes/Utils'
], function(Utils) {
    var utils = new Utils({
        arasObj: aras
    });

    var message = utils.getResourceValueByKey('message.reindex_all_items');
    showConfirmationDialog(message, function() {
        var inn = aras.newIOMInnovator();
        var resultItem = inn.applyMethod('ES_ResetAllConfigurations', '');

        if (!resultItem.isError()) {
            resultItem = inn.applyMethod('ES_PushResetQueueCommand', '');
        }

        if (resultItem.isError()) {
            aras.AlertError(resultItem.getErrorString());
        }
    });
});

//------------------------------------------------------------------------------

function showConfirmationDialog(message, callback) {
    var params = {
        buttons: {
            btnYes: aras.getResource('', 'common.yes'),
            btnCancel: aras.getResource('', 'common.cancel')
        },
        dialogHeight: 150,
        dialogWidth: 250,
        center: true,
        resizable: true,
        defaultButton: 'btnCancel',
        message: message,
        aras: aras,
        content: 'groupChgsDialog.html'
    };

    var topWnd = aras.getMostTopWindowWithAras();
    (topWnd.main || topWnd).ArasModules.Dialog.show('iframe', params).promise.then(function(resButton) {
        if (resButton === 'btnYes') {
            callback();
        }
    });
}