[TYPO3] Non-admin backend users cannot edit flexible content elements

[Pierre-Luc Drouin]

Hi,

I am trying to setup some backend users that will be able to edit pages 
and page content elements, but I am unable to figure out how to allow 
them to edit flexible content elements. Right now they can edit content 
elements such as text, but when they try to edit a flexible content 
element, the only fields they see are Type that is set to Flexible 
Content and the Header field. What could be causing that?

Thanks
Pierre-Luc Drouin