WPML config file

I'm trying to add wpml-config.xml in root directory of my theme. File has only one option:

<wpml-config>
    <custom-field action="translate">block_1</custom-field>
</wpml-config>

enter image description here

But no mater what I do options are not checked in Translation management (check image above). What am I missing here?

Solution

It's missing the main option key. It should be:

<wpml-config>
    <custom-fields> 
        <custom-field action="translate">block_1</custom-field>
    </custom-fields>
</wpml-config>

More info about WPML Language Configuration Files here: