Can someone help me?

I keep getting this result: "The 'Sales Rep Win Rates' report chart does not appear to be using a vertical bar chart" although the report dóes show a vertical bar chart.
It's in:  "Create Reports and Dashboards for Sales and Marketing Managers; "Visualize Your Data"

I tried by doing the whole trail again in a fresh/new dev org, but keep getting the same result.

I get the following message trying to install the DreamHouse app:
This app can't be installed.
There are problems that prevent this package from being installed.
Custom Field Definitions(00N6A0000098lS8) Duplicate RelationshipNameThe relationship name "Favorites__r" is already used by custom field Favorite__c.Property__c. Please rename existing relationship name.

How do I fix this?
Thanks,
Eddie

Trying to complete the "Create an approval process that validates when a Prospect Account becomes a Customer."

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: FIELD_CUSTOM_VALIDATION_EXCEPTION, Account number must be 8 characters long.: [AccountNumber]