Nodes containing simple field collection not displaying properly
I think I have found the answer, but not really the solution. I deleted the following code in my node.tpl which caused the malfunctioning of field collection:

&lt;?php if (!empty($content['links'])): ?&gt;
&lt;nav class="links node-links clearfix"&gt;&lt;?php print render($content['links']); ?&gt;&lt;/nav&gt;
&lt;?php endif; ?&gt;


But I do not understand why.