The exception is being thrown because of your second foreach
:
<div class="ui segment" data-bind="foreach: {data: stories.strings, as: 'string'}">
<p data-bind="text: string"></p>
</div>
Because you are in the context of the "stories" writing stories.strings
throws because there is no stories
property inside the stories
items so you just need to write strings
:
<div class="ui segment" data-bind="foreach: { data: strings, as: 'string' }">
<p data-bind="text: string"></p>
</div>