Getting the below error while trying to execute Challenge #4 of Lightning Experience Specialist Superbadge.

Challenge Not yet complete... here's what's wrong: 
There was an unexpected error in your org which is preventing this assessment check from completing: System.DmlException: Insert failed. First exception on row 0; first error: REQUIRED_FIELD_MISSING, Required fields are missing: [Discount_Percent__c]: [Discount_Percent__c]

Getting the below error while trying to execute Challenge #4 of Lightning Experience Specialist Superbadge.

Challenge Not yet complete... here's what's wrong: 
There was an unexpected error in your org which is preventing this assessment check from completing: System.DmlException: Insert failed. First exception on row 0; first error: REQUIRED_FIELD_MISSING, Required fields are missing: [Discount_Percent__c]: [Discount_Percent__c]

I seem to have no clue what's wrong in the report which I created. As per the requirement - Summarize the report by Account Name, the contact’s Full Name, and show the Hobby Name." Here I do not understand Full Name, as in the report we only get First Name, Last Name.
The error says - 
Challenge Not yet complete... here's what's wrong: 
The 'Lightning Hobbies by Contact' report does not appear to have either the correct report type or (most likely) the correct columns.

I have summarized the report by Account Name, then by Last Name. Another column shown is Hobbies Name. The report filter is on Hobby Type (the bucket field) = Outdoor Activities and it is locked.

Does anyone know whats wrong?