After enabling the Cache Refresh script and entering all values in Cache Refresh Configuration page, I click the button "Update and Validate Script", and then it responses with the message "Script has been executed successfully". Therefore, I click the button "Update". However, Cache Refresh is not found to be started and running (neither files are found created in the folder /var/ox/identity/cr-snapshots nor values shown for "Last run", "Updates at the last run", and "Problems at the last run" in the Cache Refresh Configuration page). What have I missed in the operation?