Only the search box and two links load unless refreshed

[miss_d_bus]

I have a website that was working perfectly until yesterday and as far as I know, no one has touched the files. When I go to it, only a search box and the first two menu links load. When I refresh the page, it then works as it should.
I cleared the cache and it has made no difference.
The site is using the latest PHP4 version of the CMS as the PHP5 isn't high enough to support it. It is on a reseller server and the other websites on CMSMS seem fine.

I found this in the error logs though:

PHP Fatal error: Call to undefined function preg_match() in /var/www/vhosts/-/httpdocs/stylesheet.php on line 11,

PHP Fatal error: Unknown function: intval() in /var/www/vhosts/-/httpdocs/plugins/function.repeat.php on line 21

PHP Fatal error: Call to undefined function file_exists() in /var/www/vhosts/-/httpdocs/modules/TinyMCE/tinyconfig.php on line 6

PHP Fatal error: Call to undefined function gettype() in /var/www/vhosts/-/httpdocs/lib/adodb_lite/adodbSQL_drivers/mysql/mysql_driver.inc on line 303

Does anyone know what this could be please?
Much appreciated,
Catherine

[calguy1000]

Only CMSMS 1.7 and 1.7.1 are supported (and 1.7 support will be dropped at the end of the month).

If you're still running 1.6.x you're on your own...sorry.