DF 2.4.0: error on GET /user/session

Hi guys,

After updating from 2.3.1 to 2.4.0 I get this error when trying to get the user session : "The ID of the user was not recognized"
This is the result:

“error”: {
“context”: null,
“message”: “The ID of the user was not recognized.”,
“code”: “sessGetPP0s01”

This is happening even if I try directly from API Docs.
Does anyone has the same issue?