Hi, 

I'm new to Salesforce and doing the beginner's admin Data Management Challenge. It keeps giving me an error message saying, 
Challenge Not yet complete... here's what's wrong: One of the contact records from the CSV file could not be found in the Org.​

Even though I've already uploaded the sample import data on my Dev Org without problems.

Any advice on this? Thank you! 
 

Very basic here.  I'm on the import to data challenge.  I walk through all of the steps and then receive an error after I get the success email.  I'm unsure on how to correct it.  I loaded 20 records and I get a success email with 20 records.  

Challenge not yet complete... here's what's wrong: 
One of the contact records from the CSV file could not be found in the Org.