User.php returns a blank page. What's wrong?

Usually an easy fix ... please see this FAQ here.

It can also be this: Blank page on profile page can be also result of identical name for search-function in two modules (names must to be unique) (Lazy Badger)

This Q&A was found on XOOPS Web Application System : https://xoops.org/modules/smartfaq/faq.php?faqid=339