fixedOrder(true) not working? I thought that a simple .fixedOrder(true) would make the files order in the same way as in the CMS. Instead of that, there is no output. Where I go wrong?

{% set files = craft.assets.kind('pdf,word,excel').fixedOrder(true) %}
&lt;section class="bestanden"&gt;
    &lt;div class="col-12-md"&gt;
        &lt;div class="documenten"&gt;
            &lt;ul&gt;
                {% for file in files %}
                &lt;li&gt;
                   &lt;i class="fa fa-file-{{ file.kind }}-o"&gt;&lt;/i&gt; &lt;a href="{{ file.url }}" target="_blank"&gt;{{ file }}&lt;/a&gt;
                &lt;/li&gt;
                {% endfor %}
            &lt;/ul&gt;

        &lt;/div&gt;
    &lt;/div&gt;
&lt;/section&gt;
fixedOrder only works with the id param. (If fixedOrder is true and id is set to a list of IDs, it will return the elements in the exact order that the IDs were listed.) It’s currently not possible to query elements in a fixed order based on any other params.

For your use case, the |group filter should work nicely:

{% set kinds = ['pdf', 'word', 'excel'] %}
{% set filesByKind = craft.assets.kind(kinds)|group('kind') %}

&lt;section class="bestanden"&gt;
    &lt;div class="col-12-md"&gt;
        &lt;div class="documenten"&gt;
            &lt;ul&gt;
                {# Loop through the file kinds in the order we want #}
                {% for kind in kinds %}
                    {% for file in filesByKind[kind] %}
                        &lt;li&gt;
                           &lt;i class="fa fa-file-{{ kind }}-o"&gt;&lt;/i&gt; &lt;a href="{{ file.url }}" target="_blank"&gt;{{ file }}&lt;/a&gt;
                        &lt;/li&gt;
                    {% endfor %}
                {% endfor %}
            &lt;/ul&gt;
        &lt;/div&gt;
    &lt;/div&gt;
&lt;/section&gt;