Create A Data Model Using Clicks

I am on the module Create a Data Model Using Clicks - I downloaded the spreadsheet House.csv - I created an org and went to the Object Manager to create a custom object from spreadsheet - I uploaded the spreadsheet - I put in House Name - clicked Next - Name is House Plural is Houses API Name is House when I click finish I get error message "API Name already exists" I did this on 2 separate computers I also created a new org - I do not have any custom objects in my Object Manager only standard objects are showing - I attached a screenshot of the message - Please help as I do not want to move on to next module until I understand why this is happening - I am redoing my modules to help me study/learn so I can pass the SFD1 certification - thank you for all your help and time!

#Trailhead Challenges