Contact Us form generates 500 error
In fact the issue is not coused neither by Contact nor by AceSEF but by your template. To solve it:
OPEN
FIND
ADD BEFORE
If you've a qualified template this should be added there but in some templates is missed, which is a must for SEF components.
OPEN
templates/YOUR_TEMPLATE/html/com_contact/contact/default_form.php
FIND
ADD BEFORE
If you've a qualified template this should be added there but in some templates is missed, which is a must for SEF components.