We couldn’t reproduce the defect on our account. In the past when similar errors showed up, it has been because of conflicts with themes using bootstrap. That issue was fixed with the latest update.
We also have a standalone version of Contenido that’s a bit more robust than the WordPress plugin. Would you be interested in trying that version and see how it fits your needs?
If so, please email me to [email protected] and I’ll share more details.
Thank you,
Martin