unable to submit completed form

http://http://thedistricttl.com/enews-signup/

If I do not fill in all of the required fields and hit ‘submit’, it alerts me as to which ones need to be completed. This is the expected behavior.

But, if I fill in the form completely and hit submit – nothing happens. I don’t get the expected confirmation. I don’t believe it is a problem that the email hasn’t been sent, because according to FAQ page, form submissions will always be saved in the database whether or not the email was sent. I don’t see that happening. I believe the failure is occuring before VFB even attempts to send the email.

I have done the following – all without success:
– upgraded to the latest version of WP (3.8.1),
– upgraded to the latest version of all active plugins (including VFB):
Advanced Menu Widget, version 0.3
Enhanced Text Widget, version 1.4.3
Events Manager, version 5.5.2
List category posts, version 0.46.4
NextGEN Gallery by Photocrati, version 2.0.61
Print-O-Matic, version 1.5.3
Text Control, version 2.3.1
Visual Form Builder, version 2.8
WordPress SEO, version 1.5.2.6
– deactivated all plugins with the exception of VFB,
– played with the settings for VFB,
– changed confirmation from ‘text’ to ‘page’ (I selected the home page for this test),
– changed “Reply-To E-mail” and “E-mail(s) To” to the same (valid) email account ‘[email protected]’

https://ww.wp.xz.cn/plugins/visual-form-builder/