HostFLV.com :: FFMPEG Hosting - Knowledgebase - HELP my php script doesn’t work or I have an error message

Check that the PHP script that you are attempting to execute has permissions of no more than 755 - 644 will work just fine normally, this is not something that will need to be changed in most cases.
Check that the chmod permissions for the folder that the script resides in are set to a maximum of 755. This also includes folders that the script would need to have access to also.
Check that the files are owned by you i.e. not owned by user ‘nobody’. Certain applications having been run under PHP as an Apache module, may have files owned by the Apache user - In that case, submit a helpdesk ticket for the file ownerships to be changed.
Check that you do not have an .htaccess file with php_values within it. They will cause a 500 Internal server error, when attempting to execute the script. The php_values will need to be removed from your .htaccess file and a php.ini put in its place, containing the PHP directives as explained above.