We all developers love CMS platforms. It gives a platform which is configurable and well designed. We manually have to reuse the elements and blocks. Loads of extensions and plugins are available and they are easy to configure. But can you imagine your site is showing all white blank pages.
White Screen of Death is one of the worst thing you can face in web development. This error is can be caused by many possible reasons and it is very hard to debug what is cause of this if you face this.
Different causes of WSOD can be,
1. Whitespace at the End of a PHP File
2. PHP4 Syntax Errors and Incompatibility
3. Multiple versions of PHP
4. Invisible Errors for Developers
5. Implement Hook Twice
6. Output Buffering for modules
7. PHP Memory Limits
Some unwanted changes in core of module, Code can be main cause of this. If you don’t have well document changes that it is better to check the log file. If undo changes does not work for you try,
1. Ensure you have proper PHP Configuration, no PHP syntax errors or memory limit
2. Renaming directory name of bad module can temporary ignore that module
3. Clearing the Cache Table
4. Restarting Web server
5. Increase default PHP timeout
For Drupal, Any changes in Drupal’s default module or code must be avoided.
You can read more about this issue on Drupal.org.
There are multiple solutions for these kind of situations on web choose wisely.