Magento shows blank/empty page. How do I solve this?

Symptoms

Blank page or white screen is shown in Magento Frontend, Backend or Magento Connect Manager.

 

Cause

If you see a blank page / white screen opening your Store in browser, it indicatesthat there is a PHP fatal error somewhere in the code of your Magento store.

This usually happens when you modified files, theme templates or modules / extensions, or installed a theme or extension which cause fatal PHP errors.

 

Troubleshooting

Before starting investigation please try toDisable Magento Compiler andClear cached Magento data , in the most cases it should solve the issue.

To see the actual error message you need to login via FTP to your Store and use the following instructions:

• Download the index.php file to your computer
  Note: for troubleshooting Magento Connect Manager changes should be done todownloader/index.php file
• Edit the downloaded index.php file and uncomment (by removing leading hash character) the following code:

  ini_set('display_errors', 1);
  
  
  

  or insert this line somewhere at the top of the file.
  Note: for troubleshooting Magento Connect Manager changes should be done todownloader/index.php file
• Try to increase PHP memory limit up to 256Mb or more by adding the following line intoindex.php right after ini_set('display_errors',1):
  
  ini_set('display_errors', 1); ini_set('memory_limit', '256M');

• Upload the modified index.php file back (you can also rename originalindex.php to index.php.orig to be able to revert the changes)
• Refresh Magento Store page in your browser, you should see the PHP error message now
• Look for the solution by narrowing down search results with your error message

Please do not forget to change 'display_errors' setting back when the issue is solved.

 

If the error report gives no clue, to solve the issue please use the following steps:

• Rollback all recent changes you applied to your store
• Clear cached Magento data
  
• Disable Magento Compiler
• One by one, disable recently installed modules by changing <active>true</active> to <active>false</active> inapp/etc/modules/<MODULE_NAME>.xml, where <MODULE_NAME> should be replaced with actual module name you installed recently.Flush Magento cache after each operation.
  
• If you recently installed some theme, try to switch interface to a previously used one. If you can not reach admin interface, you can rename / move out theme directory underapp/design/frontend/<theme_package>/<theme_name>, where <theme_package>/<theme_name> is path to your theme.Flush Magento cache after each operation. Magento will switch to default theme if it can not find a custom one.
  
• Contact Support Team, providing the error log record and URL, throwing the error report

原文地址：http://kb.magenting.com/content/22/38/en/magento-shows-blank-empty-page-how-do-i-solve-this.html