"Object of class Craft\ElementCriteriaModel could not be converted to string" in Craft CP After updating some fields for entry types and submitting new entries, I'm getting a "Object of class Craft\ElementCriteriaModel could not be converted to string" in the Craft control panel upon trying to access any of the entries. 

I can still create entries, but once created, I cannot access it again.

Any idea how to troubleshoot this?

The error it's giving back to me is on line 34

craft/app/templates/entries/_edit.html(34)

22         {% if not isVersion %}
23             &lt;input type="hidden" name="sectionId" value="{{ section.id }}"&gt;
24             {% if entry.id %}&lt;input type="hidden" name="entryId" value="{{ entry.id }}"&gt;{% endif %}
25             {% if craft.isLocalized() %}&lt;input type="hidden" name="locale" value="{{ entry.locale }}"&gt;{% endif %}
26         {% else %}
27             &lt;input type="hidden" name="versionId" value="{{ entry.versionId }}"&gt;
28         {% endif %}
29 
30         &lt;div class="grid first"&gt;
31             &lt;div class="item" data-position="left" data-min-colspan="2" data-max-colspan="3"&gt;
32                 &lt;div id="fields" class="pane"&gt;
33                     {% include "_includes/tabs" %}
34                     {% include "entries/_fields" with {
35                         static: isVersion
36                     } %}
37                 &lt;/div&gt;
38             &lt;/div&gt;&lt;!--/item--&gt;
39 
40             &lt;div class="item" data-position="right" data-colspan="1"&gt;
41 
42                 {% if showPreviewBtn %}
43                     {% include "_includes/previewbtns" %}
44                 {% endif %}
45 
46                 {% if craft.isLocalized() and section.getLocales() | length &gt; 1 %}
This was caused by an incorrectly configured assets field in the entry type. The upload location had an invalid variable set in the path.