PHP 4.2.0 or higher

[Alden]

I've been using version 5 Pro for over a year with no problems. But when I upgraded to V6 Pro, indexed the site, uploaded the zoom files, and attempted to use the search engine, I got the error message: "This version of the Zoom search script requires PHP 4.2.0 or higher.
You are currently using: PHP 4.1.2"

What is this referring to? The version of PHP used on the host servers, or something at my end?

[David]

It is refering to the version of PHP being used on the server where you are running the PHP script.

PHP4 was released in May 22, 2000. About 10 years ago now.
We no longer support PHP4.0 nor PHP4.1 (released in 2001).

PHP5 was released in 2004. About 6 years ago.

For security reasons if nothing else you should move to PHP 5.3. If if you must stay on PHP4, then at least get PHP4.4