I cannot seem to pass this one simple challenge.  I've attempted it with my regular playground, my current DE Org, and setup a new DE with no  success.  The following message came through each time so I am assuming it's on Salesforce's side: "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: CXHRJNMD"

I cannot seem to pass this one simple challenge.  I've attempted it with my regular playground, my current DE Org, and setup a new DE with no  success.  The following message came through each time so I am assuming it's on Salesforce's side: "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: CXHRJNMD"