Issue: 


I have used the latest version of BSS feed and it's showing blank

Also i would like to inform you that if i removed below mentioned line it's corrected


<field id="controller" translate="label" sortOrder="10" showInDefault="1" showInWebsite="1" showInStore="1">
                    <label>Exclude Controllers</label>
                    <frontend_model>Bss\DeferJS\Block\System\Form\Field\Regex</frontend_model>
                    <backend_model>Magento\Config\Model\Config\Backend\Serialized\ArraySerialized</backend_model>
                    <comment><![CDATA[Listed controllers will be unaffected by defer javascript. Use: {module}_{controller}_{action}.]]></comment>
                </field>
                <field id="path" translate="label" sortOrder="20" showInDefault="1" showInWebsite="1" showInStore="1">
                    <label>Exclude Paths</label>
                    <frontend_model>Bss\DeferJS\Block\System\Form\Field\Regex</frontend_model>
                    <backend_model>Magento\Config\Model\Config\Backend\Serialized\ArraySerialized</backend_model>
                    <comment><![CDATA[Listed paths will be unaffected by defer javascript. Use: (Example: gear/bags.html).]]></comment>
                </field>


Also on frontend getting error of "error in unserialized" as  value of $regex ('deferjs/general/controller' and 'deferjs/general/path') showing blank("a:0:{}")

I have upgraded our Magento to 2.2.3


Solution:

The root of problem is due to on magento version 2.2.x, the storing data is different from the version 2.1.x, to fix this issue, you should remove two below rows on core_config_data table :


deferjs/general/path

deferjs/general/controller


Please note that if you have settings of Defer Javascript before, please back up before deleting because it could be lost.


For more information about product, please refer Defer JavaScript for Magento 2.

If you need any further assistance, please feel free to contact us.
Please visit our site for more useful Magento 2 Extensions: https://bsscommerce.com/magento-2-extensions.html