Just recently moved a domain from another host to my newly setup Debian Wheezy nginx setup on a VPS. For some reason I kept getting error 500 trying to load a page no matter what I did. Checked the logs and saw Code: FastCGI sent in stderr PHP Parse error: syntax error, unexpected 'array' (T_ARRAY) while reading response header from upstream /var/www/clients/client2/web1/web/wp-includes/formatting.php on line 1691 Line 1691 in the formatting.php file is pretty short: Code: return $matches; After trying all the suggested site moving fixes I could find, like changing the .htaccess file, disabling plugins & themes, etc. - it occured to me that I had already moved another site that was using Wordpress and it had worked without any issues. Further investigation revealed the working site was using Wordpress 3.8.3. So I downgraded the non working site from 3.9 to 3.8.3 and it worked instantly. So the question is - Why did 3.9 break? PHP is on PHP Version 5.4.4-14+deb7u9 MySQL version is 5.5.37-0+wheezy1 Any ideas? Has anybody else seen this issue yet?