Hi Daniel,

The mega menu is a 3rd party plugin not supported officially by our theme so it can cause problems to you because of it's functionality with the theme, they may be conflicting each other, if you're having issues with the menu then we can check it but firstly you will need to give us access to your site since we cannot access it.

Hi Daniel,

After checking functions.php file, I saw you have added this code:

function payment_gateway_disable_country( $available_gateways ) {
    global $woocommerce;
    $country = !empty($woocommerce->customer->get_shipping_country()) ? $woocommerce->customer->get_shipping_country() : $woocommerce->customer->get_country();
    if ( isset( $available_gateways['cod'] ) && $country <> 'SK' ) {
        unset(  $available_gateways['cod'] );
    }
    return $available_gateways;
}
add_filter( 'woocommerce_available_payment_gateways', 'payment_gateway_disable_country' );

And on menu page generates this error:

(view large version)

function payment_gateway_disable_country( $available_gateways ) {
    global $woocommerce;
    // Firstly check if customer already is set
    if ( $woocommerce->customer ) {
	    $country = !empty($woocommerce->customer->get_shipping_country()) ? $woocommerce->customer->get_shipping_country() : $woocommerce->customer->get_country();
	    if ( isset( $available_gateways['cod'] ) && $country <> 'SK' ) {
	        unset(  $available_gateways['cod'] );
	    }
    }
    return $available_gateways;
}
add_filter( 'woocommerce_available_payment_gateways', 'payment_gateway_disable_country' );

So this IF condition: if ( $woocommerce->customer )  will check if the customer is set on $woocommerceglobal variable.

Now the menu page can be opened. 

Hahaha, thanks Daniel, I am glad that its now working fine for you.

You are more than welcome