INVALID_REQUEST, description:Trading account is not authorized

I'm using the WPF sample application to test accessing symbol data and executing trades, this is the output from

Authorize Application:

Send: ProtoMessage{AppAuthRequest{clientId:***correct value***}}
Received: ProtoMessage{ApAuthResponse, clientMsgId:Client Message}

Get Accounts List
Send: ProtoMessage{GetAccountsByAccessTokenReq}
Received: ProtoMessage{GetAccountsByAccessTokenRes{ID: ***** Status: Live
ID: ***** Status: Live
}, clientMsgId:Client Message}
Send: ProtoMessage{CreateOrderRequest{}}

I can't select any accounts in the accounts dropdown and If I select anything to do with symbols or deals, I get this error:

Received: ProtoMessage{ErrorResponse{errorCode:INVALID_REQUEST, description:Trading account is not authorized}, clientMsgId:Client Message}