Cannot assign null to property Modules\Cms\Helpers\PublicApi\Cart::$cartId of type string

TypeError Object
(
    [message:protected] => Cannot assign null to property Modules\Cms\Helpers\PublicApi\Cart::$cartId of type string
    [string:Error:private] => 
    [code:protected] => 0
    [file:protected] => /var/www/erp.netorigo.com/Modules/Cms/Helpers/PublicApi/Cart.php
    [line:protected] => 59
    [trace:Error:private] => Array
        (
            [0] => Array
                (
                    [file] => /var/www/erp.netorigo.com/NetOrigo/Site/Seo.php
                    [line] => 242
                    [function] => __construct
                    [class] => Modules\Cms\Helpers\PublicApi\Cart
                    [type] => ->
                )

            [1] => Array
                (
                    [file] => /var/www/erp.netorigo.com/NetOrigo/Site/Seo.php
                    [line] => 283
                    [function] => getDatalayerCheckout
                    [class] => NetOrigo\Site\Seo
                    [type] => ->
                )

            [2] => Array
                (
                    [file] => /var/www/erp.netorigo.com/NetOrigo/Site/Seo.php
                    [line] => 158
                    [function] => setDataLayer
                    [class] => NetOrigo\Site\Seo
                    [type] => ->
                )

            [3] => Array
                (
                    [file] => /var/www/erp.netorigo.com/Modules/Cms/PublicModule.php
                    [line] => 543
                    [function] => getMetaTags
                    [class] => NetOrigo\Site\Seo
                    [type] => ->
                )

            [4] => Array
                (
                    [file] => /var/www/erp.netorigo.com/NetOrigo/Application/WebApplication.php
                    [line] => 324
                    [function] => dispatch
                    [class] => Modules\Cms\PublicModule
                    [type] => ->
                )

            [5] => Array
                (
                    [file] => /var/www/erp.netorigo.com/NetOrigo/Application/BaseApplication.php
                    [line] => 134
                    [function] => doExecute
                    [class] => NetOrigo\Application\WebApplication
                    [type] => ->
                )

            [6] => Array
                (
                    [file] => /var/www/erp.netorigo.com/public/index.php
                    [line] => 12
                    [function] => execute
                    [class] => NetOrigo\Application\BaseApplication
                    [type] => ->
                )

        )

    [previous:Error:private] => 
)