I have completed every challenge but this. Everything seems like normal but system keeps telling me this error:

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: [Service__c]: [Service__c]

I tried same challange with my another account to make sure i am not doing it wrong, and it's accepted by trailhead. But with this account it keeps telling that error. Don't know what to do, any clue?

 

I have completed every challenge but this. Everything seems like normal but system keeps telling me this error:

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: [Service__c]: [Service__c]

I tried same challange with my another account to make sure i am not doing it wrong, and it's accepted by trailhead. But with this account it keeps telling that error. Don't know what to do, any clue?

 

I completed the challenge, earning the Force.com basics and Date Modeling badges, however I did so under a different login than my Salesforce employee login. I was having trouble accessing the developer zone and created a seperate account for it. Can I have the badges under my developer edition login transferred to my normal Salesforce employee login and am I still qualified for the t-shirt giveaway?