[Solved]fatal error uncaught error call to undefined function eregi() in

Warning This function was DEPRECATED in PHP 5.3.0, and REMOVED in PHP 7.0.0.

Alternatives to this function include:

• preg_match() (with the i (PCRE_CASELESS) modifier)

This function is since PHP 5.3.0 deprecated. It’s not recommended to use any more.

(http://php.net/manual/en/function.eregi.php)

So you could instead
–  PHP-Version downgrade
-Replace all occurrences of eregi by preg_match, according to the pattern

Credit:  VoinG