If you have remitted contributions for November 16 on or before 17th December 16, then the old ECR was functioning. The new ECR will automatically open when you process remittance for December 16. However, all PF accounts should be UAN linked; contributions of non-activated UAN accounts will not be uploaded.
This is an intermediate step of PF authorities. Most probably, they may do away with employees' PF number and operate only the UAN of the employee.