I'm migrating to odoo 16. I have a widget MediaButton. 
But for some reason odoo can't mount it properly. 
I see an error message in the debugger console:

Missing widget: media_button for field of type boolean

What could be the reason?



odoo.define('media-button.main', function (require) {
    const AbstractField = require('web.AbstractField');
    const registry = require('web.field_registry');

    const STATE_SHOW_PLAY = 'play';
    const STATE_SHOW_PAUSE = 'pause';
    const STATE_SHOW_STOP = 'stop';

    const MediaButton = AbstractField.extend({

    });

    registry.add('media_button', MediaButton);
});

some view contains this widget
...
<div class="mb-4">
   <field name="on_off" widget="media_button" nolabel="1" force_save="1"/>
</div>
...
Console error

Missing widget: media_button for field of type boolean