<?xml version="1.0" ?>

<container xmlns="http://symfony.com/schema/dic/services"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd">

    <parameters>
        <parameter key="admingenerator.twig.extension.form.class">Admingenerator\FormBundle\Twig\Extension\FormExtension</parameter>
    </parameters>
    
    <services>
        
        <service id="admingenerator.twig.extension.form" class="%admingenerator.twig.extension.form.class%" lazy="true">
            <tag name="twig.extension" />
            <argument type="service" id="twig.form.renderer" />
        </service>

    </services>

</container>

<?xml version="1.0" ?>

<container xmlns="http://symfony.com/schema/dic/services"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd">

    <parameters>
        <parameter key="admingenerator.twig.extension.form.class">Admingenerator\FormBundle\Twig\Extension\FormExtension</parameter>
    </parameters>
    
    <services>
        
        <service id="admingenerator.twig.extension.form" class="%admingenerator.twig.extension.form.class%">
            <tag name="twig.extension" />
            <argument type="service" id="twig.form.renderer" />
        </service>

    </services>

</container>

Fix 'extension not enabled' error
Fix 'extension not enabled' error