how to correct this Challenge not yet complete in My Trailhead Playground 1 The field 'Loan_Amount__c' either does not exist on the Contact object or it is not of type currency.

Hi, 

Go to Object Manager > Contact > Page Layout > Page Layout Assignment (button top right) and assign the "Contact Layout" to all profiles.

Also make sure the field Loan_Amount__c has Field Level Security enabled for all Profiles.

Re-Check challenge again.