The error indicates that the currently configured User of the Riva connection for Oracle CRM On Demand has Web Services disabled / de-activated.
Contact Oracle CRM On Demand support to have the account re-activated.
The error code reference for the support request is: [ErrorCode] SBL-ODU-01006
The error occurs while using the “Intergration API” during the “login” command.
Omni.ConnectionException: Login Denied: User account not yet activated for Web Services. Please try again later.