If you create a feed with an empty message template field you get this:
The error message is outputed by the phrase please_enter_value_for_required_field_x = Please enter a value for the required field '{field}'. In this case, the {field} variable in the phrase is 'message_template'. The error is that not the content of the phrase is displayed, but just the phrase itself.
In case this is not "as designed", I suggest changing it the way it displays the actual content of the, in this case, 'message_template' phrase:
Please enter a value for the required field 'Message Template'.
The error message is outputed by the phrase please_enter_value_for_required_field_x = Please enter a value for the required field '{field}'. In this case, the {field} variable in the phrase is 'message_template'. The error is that not the content of the phrase is displayed, but just the phrase itself.
In case this is not "as designed", I suggest changing it the way it displays the actual content of the, in this case, 'message_template' phrase:
Please enter a value for the required field 'Message Template'.
