I'm doing the simple lightning components challenge and have hit this problem in my existing trailhead org and a brand new dev org that I've just created:

Challenge not yet complete... here's what's wrong: 
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: QVWBQHAG

Getting this error when I run the challenge even though I created the object per the recipe in my DE, and it even shows that it's there in the screen that appears when I log into the Developer Edition from the Trailhead screen.  I had created the object, and then at the point of running the challenge earlier was getting repeated errors on trying to connect to the server.  Now I'm home, running from a different computer (that's what being on the cloud's about, right?) and my work so far isn't recognized.  Should I delete the object and go through the steps again?

This challenge seems simple enough but I'm stuck and any help would be appreciated. 

So the Challenge is Create a validation rule to check that a contact is in the zip code of its account. here is the question below:
To complete this challenge, add a validation rule which will block the insertion of a contact if the contact is related to an account and has a mailing postal code (which has the API Name MailingPostalCode) different from the account's shipping postal code (which has the API Name ShippingPostalCode).Name the validation rule 'Contact must be in Account ZIP Code'.
A contact with a MailingPostalCode that has an account and does not match the associated Account ShippingPostalCode should return with a validation error and not be inserted.
The validation rule should ONLY apply to contact records with an associated account. Contact records with no associated parent account (hint: you can use the ISBLANK function for this check) can be added with any MailingPostalCode value

Here is my  work.. Any help would be appreciated.. thanks, 

Rule Name Contact_must_be_in_Account_ZIP_Code Active [Checked]
Error Condition Formula AND( BillingPostalCode = ShippingPostalCode )
Error Message Billing zipcode does not match the Shipping Zipcode Error Location Billing Zip/Postal Code