Challenge "Set Up Apex Replay Debugger" Step "Authorize an Org" i get an error "Could not retrieve the username after successful auth code exchange." and the web page displays OAuth Error REST API is not enabled.

Challenge "Set Up Apex Replay Debugger"  Step "Authorize an Org" i get an error  "Could not retrieve the username after successful auth code exchange." and the web page displays OAuth Error REST API is not enabled. 

Ive looked at the forum responses and they are not helpful.  I have checked a lot of the profiles and the API is enabled.