Misconfigured folder or file permissions
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Last modified: November 11, 2009 - 05:10
Check your Drupal file or folder permissions. Permissions means read and write accesses. They are maybe misconfigured. This is one of the most likely cause of this error.
For Drupal 6 read more at http://drupal.org/getting-started/6/install/set-permissions
Read the INSTALL.txt file that comes with Drupal. There is a section in there about permissions.