Craft renders unwanted quotation marks on some tags Breaking my head over this. 

On one of the tags in the HTML template. The {% for image in category.CategorieImage %} loop. Craft seems to generate 2 unwanted quotation marks ("). These characters are messing up the lay-out as the generate an unwanted line/paragraph.

            &lt;div class="portfolio-item img-thumbnail"&gt;
            &lt;a href="{{ category.url }}" class="thumb-info secundary"&gt;
                {% for image in category.CategorieImage %}
                &lt;img class="img-responsive" src="{{ image.url ('categorieimage') }}" title="{{ category.title }}" alt="{{ category.title }}"&gt;
                {% endfor %}
                &lt;span class="thumb-info-title"&gt;
                    &lt;span class="thumb-info-inner"&gt;{{ category.title }}&lt;/span&gt;
                    &lt;span class="thumb-info-type"&gt;{{ category.categorieDescription[:80] ~ '...' }}&lt;/span&gt;
                &lt;/span&gt;
                &lt;span class="thumb-info-action"&gt;
                    &lt;span title="Universal" class="thumb-info-action-icon"&gt;&lt;span class="badge"&gt;{{ entriesNbr }}&lt;/span&gt;&lt;span class="nameMythes"&gt;Mythes&lt;/span&gt;&lt;i class="fa fa-link"&gt;&lt;/i&gt;&lt;/span&gt;
                &lt;/span&gt;
            &lt;/a&gt;
        &lt;/div&gt;


This is what's rendered on the final page in Safari using the developers panel:

&lt;div class="portfolio-item img-thumbnail"&gt;
            &lt;a href="http://commercielemythes.nl/mythes/sales" class="thumb-info secundary"&gt;
                                    &lt;img class="img-responsive" src="http://commercielemythes.nl/assets/categorie_image/_categorieimage/Sales.jpg" title="Sales" alt="Sales"&gt;
                "  "
                &lt;span class="thumb-info-title"&gt;
                    &lt;span class="thumb-info-inner"&gt;Sales&lt;/span&gt;
                    &lt;span class="thumb-info-type"&gt;Over succes in sales zijn vele mythes. Velen zijn inmiddels zo geworteld dat ze ...&lt;/span&gt;
                &lt;/span&gt;
                &lt;span class="thumb-info-action"&gt;
                    &lt;span title="Universal" class="thumb-info-action-icon"&gt;&lt;span class="badge"&gt;5&lt;/span&gt;&lt;span class="nameMythes"&gt;Mythes&lt;/span&gt;&lt;i class="fa fa-link"&gt;&lt;/i&gt;&lt;/span&gt;
                &lt;/span&gt;
            &lt;/a&gt;
        &lt;/div&gt;


I've used CODA to show any unwanted (invisible) characters but none seems to be there.
I believe the quotation marks are misleading... What you're seeing in the Safari developers panel is simply a blank space, and Safari is putting quotes around it because it's being interpreted as a "string" by the browser.

Equally, your visual layout is probably just getting screwed up because of empty space between your HTML tags. If you tightened up your HTML tags and removed any spacing in between, the layout might look as you expect it to.

You can easily trim whitespace around Twig tags by using spaceless, or adding dashes.

{% spaceless %}
    &lt;a href="#"&gt;
        &lt;img src="path/to/img" /&gt;
    &lt;/a&gt;
{% endspaceless %}


Remove whitespace before:

{%- for entry in entries %}


Remove whitespace after:

{% for entry in entries -%}


Remove whitespace before &amp; after:

{%- for entry in entries -%}