Step not yet complete in My Trailhead Playground 1 There was an unexpected error in your org which is preventing this assessment check from completing: System.DmlException: Update failed. First exception on row 0 with id 001Qy000016tBBnIAM; first error: R

Hi , 

I think the settings for the previous challenge remain. Please deactivate. 

Setup-->Object Manager --> Choose (Account)-->Fields-->Edit(Price__c) and uncheck required