WSOD on node edit/view pages only after migration - subdomain multisite
You have to also turn on display_errors (see the examples section of http://php.net/manual/en/function.ini-set.php ).

Usually when display_errors is off php is configured to log errors to some file. You might want to find that file and look at it.

My guess would be that some php-module is missing on that server and some drupal-module that is active on node-edit forms tries to use a function from that php-module.