To get WordPress to display errors, edit the wp-config.php file to say define( ‘WP_DEBUG’, true ); By default, this is set to false and should be towards the bottom of the file. That will allow you to see which errors are being produced. Also, whitespace at the end of files almost never causes the WSOD; … Read more
There were wp files in the web root which had file size of 0 bytes. Uploading proper copies from the zip file resolved the problem. The same cause of the problem has occurred to me quite a few times in the past, but I had forgotten it.
wp() is quite essential function. It resides in functions.php file (don’t confuse with functions.php in theme, different thing) and I don’t think you can load WP without passing require directive for that file at some point. So your install seems very broken – either functions.php file in core is damaged or something else is broken … Read more
There is a bug in WordPress 3.3.1 causing the issue. It may affect other versions as well. To solve the issue you can update WordPress to the current stable release and do integration testing afterwards. Or you can do a quick bug fix. To fix the bug: Open file blog/wp-admin/includes/screen.php in your favorite text editor. … Read more