[VE][46] ">" in first line of Page

I have joomla on url:  www.trgovina-cokla.net  .And the problem is in which
file of joomla. Tried to find it index.php any many other files. Can I fix
that it wont show on top of page, on first line    ">" 

I would be very thankfull for your answer.

 

Validating http://www.trgovina-cokla.net/ 
Error [46]: "character X not allowed in prolog"