Data Security Module "Control Access to Fields"

Hi there. I'm trying to complete the Data Security Module "Control Access to Fields", but whenever I try to edit an Object I get the following error- "Unable to Access Page The value of the "id" parameter contains a character that is not allowed or the value exceeds the maximum allowed length. Remove the character from the parameter value or reduce the value length and resubmit. If the error still persists, report it to our Customer Support team. Provide the URL of the page you were requesting as well as any other related information." I get the error regardless of which object I choose.