Dependency on a non-existent service "SonataMedia/MediaAdmin/inner_row_media.html.twig"

Using Sonata's Easy Extends tool, I am extending the MediaAdmin base class and overriding the existing service for that class. In doing so, I've converted this XML service definition (in the vendor folder):

    <service id="sonata.media.admin.media" class="%sonata.media.admin.media.class%" public="true">
        <tag name="sonata.admin" manager_type="orm" group="%sonata.media.admin.groupname%" label_catalogue="%sonata.media.admin.media.translation_domain%" label="media" label_translator_strategy="sonata.admin.label.strategy.underscore" icon="%sonata.media.admin.groupicon%"/>
        <argument/>
        <argument>%sonata.media.admin.media.entity%</argument>
        <argument>%sonata.media.admin.media.controller%</argument>
        <argument type="service" id="sonata.media.pool"/>
        <argument type="service" id="sonata.media.manager.category" on-invalid="null"/>
        <call method="setModelManager">
            <argument type="service" id="sonata.media.admin.media.manager"/>
        </call>
        <call method="setTranslationDomain">
            <argument>%sonata.media.admin.media.translation_domain%</argument>
        </call>
        <call method="setTemplates">
            <argument type="collection">
                <argument key="inner_list_row">@SonataMedia/MediaAdmin/inner_row_media.html.twig</argument>
                <argument key="outer_list_rows_mosaic">@SonataMedia/MediaAdmin/list_outer_rows_mosaic.html.twig</argument>
                <argument key="base_list_field">@SonataAdmin/CRUD/base_list_flat_field.html.twig</argument>
                <argument key="list">@SonataMedia/MediaAdmin/list.html.twig</argument>
                <argument key="edit">@SonataMedia/MediaAdmin/edit.html.twig</argument>
            </argument>
        </call>
    </service>

... into this yaml:

sonata.media.admin.media:
    class: App\Application\Sonata\MediaBundle\Admin\ORM\MediaAdmin
    arguments:
        - ''
        - '%sonata.media.admin.media.entity%'
        - '%sonata.media.admin.media.controller%'
        - '@sonata.media.pool'
        - '@sonata.media.manager.category'
    tags:
        - { name: sonata.admin, manager_type: orm, group: admin, label: Seiten }
    public: true
    calls:
        - [ setModelManager, ["@sonata.media.admin.media.manager"] ]
        - [ setTranslationDomain, ["%sonata.media.admin.media.translation_domain%"] ]
        - [ setTemplates, [ inner_list_row : "@SonataMedia/MediaAdmin/inner_row_media.html.twig", outer_list_rows_mosaic : "@SonataMedia/MediaAdmin/list_outer_rows_mosaic.html.twig", base_list_field : "@SonataAdmin/CRUD/base_list_flat_field.html.twig", list : "@SonataMedia/MediaAdmin/list.html.twig", edit : "@SonataMedia/MediaAdmin/edit.html.twig" ] ]

The yaml parses just fine when I try running a cache warmup. The problem, however, is that I now get this error message:

The service "sonata.media.admin.media.template_registry" has a dependency on a non-existent service "SonataMedia/MediaAdmin/inner_row_media.html.twig".

This seems strange to me, since the version of the admin service definition in the vendor folder (which was working fine before I overrode it) also has this same dependency. Any ideas about what's going wrong, and what I can do to fix it?

The @ sign in a definition typically tells the compiler to look for a service with that name. If you are using it as a template namespace you will probably have to escape the symbol. Try this:

    <call method="setTemplates">
        <argument type="collection">
            <argument key="inner_list_row">@@SonataMedia/MediaAdmin/inner_row_media.html.twig</argument>
            <argument key="outer_list_rows_mosaic">@@SonataMedia/MediaAdmin/list_outer_rows_mosaic.html.twig</argument>
            <argument key="base_list_field">@@SonataAdmin/CRUD/base_list_flat_field.html.twig</argument>
            <argument key="list">@@SonataMedia/MediaAdmin/list.html.twig</argument>
            <argument key="edit">@@SonataMedia/MediaAdmin/edit.html.twig</argument>
        </argument>
    </call>