To complete the CPQ Billing Specialist challenge I signed up for the Developer Edition Org with Salesforce Billing and Salesforce CPQ per the instructions.  In order to complete Challenge 2 it is necessary to edit the page layout of the Consumption Schedule Object.  When I try to edit a page layout on this object, or any other object I am getting this message
"Unable to Access Page - The value of a 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."  Any ideas how to fix?