3587027 - EC-to-ECP: Error '301 - The system failed to request a service response' while opening Direct Pay Statement.

While opening Direct Pay Statement from employee's profile in EC, the error:

• Error Code: 301
• Error Message: The system failed to request a service response.

This may also happen in the Payroll System Information screen. 

• SAP SuccessFactors Employee Central Payroll 
• Pay Statement

Employee Central Payroll, OAuth, Error ID, Gateway Service, Payroll System Information, Direct Pay Statement, HRSFEC_PAY_OVERVIEW_SRV_0001, HTTP/1.1 404  NOT FOUND, PAYROLL_ECPSERVICEHANDLER_601_FAILED_REQUEST_CSRF_TOKEN?, Service Unavailable, odatav4/payroll/ecp/paystatement/v1/$batch  , KBA , LOD-EC-ECP-SF-PST , EC Payroll Pay Statement , Problem