The server generally expects files such as HTML, Images, and other media to have a permission mode of 644. The server you are on runs applications in a very specific way in most cases. If you have made changes to the file ownership on your own through SSH please reset the Owner and Group appropriately. The server generally expects files and directories be owned by your specific user cPanel user.
Some of these are easier to spot and correct than others. There are a few common causes for this error code including problems with the individual script that may be executed upon request.
