The challenge in this trailhead https://trailhead.salesforce.com/modules/sales_admin_sales_reports_for_lex/units/sales_admin_sales_reports_unit_3 is giving the error . Error is 
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: KMBSDJYC