I'm completing the Build Logic to Reassign Accounts module and I'm getting an error message. 
There was an unexpected error while verifying this challenge. Usually this is due to some pre-existing configuration or code in the challenge Org. We recommend using a new Developer Edition (DE) to check this challenge. If you're using a new DE and seeing this error, please post to the developer forums and reference error id: SAXMCOYT
 

I am trying to use the Field Footprint app to determine the usage of fields on a custom object.  I'm getting an error message that the last referenced date is inaccessible?  What do I need to do to resolve that so that I can pull the data I'm needing?  I'm not finding anything in the Field Footprint user guide on this.  Please advise.  Thank you.