[Plugin: WordPress SEO by Yoast] 0.2.5.1 triggers fatal error

Error is:

Parse error: parse error, unexpected T_STRING, expecting T_OLD_FUNCTION or T_FUNCTION or T_VAR or ‘}’ in /index/wp-content/plugins/wordpress-seo/admin/class-metabox.php on line 35

What version of PHP are you running?

Same here:

Parse error: syntax error, unexpected T_STRING, expecting T_OLD_FUNCTION or T_FUNCTION or T_VAR or ‘}’ in /html/laboratory/wp-content/plugins/wordpress-seo/admin/class-metabox.php on line 35

PHP Version appears to be 4.4.8 according to <?php phpinfo(); ?>

Yeah PHP5 is required for this plugin now as is it for WordPress starting with WordPress 3.2:

https://codex.www.ads-software.com/Switching_to_PHP5