Where you'll find your PHP error log will depend on your server's setup. In most shared hosts, there is a directory called
logs or something similar. If your service provider has a knowledge base, they will typically describe how to find your logs there.
If you're running your own server, logs will usually be somewhere like
There are many useful threads in StackOverflow that may help to find your logs. For example: http://stackoverflow.com/questions/5127838/where-does-php-store-the-error-log-php5-apache-fastcgi-cpanel