INSUFFICIENT_ACCESS: EntityObject can not be initialized with null EntityInfo

Hi everbody!   

I have an integration SOAP to update profiles.  But since last week this integration stop working.    This is the error from integration and PostMan tests:  INSUFFICIENT_ACCESS: EntityObject can not be initialized with null EntityInfo 

  I have admin profile with all permission: Modify all data, customize application....and so on.    This is the request from postman:  <?xml version="1.0" encoding="utf-8"?>

<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:tns="http://soap.sforce.com/2006/04/metadata">

  <soap:Header>

    <tns:SessionHeader>

        <tns:sessionId>[MY_SESSION_ID]</tns:sessionId>

    </tns:SessionHeader>

  </soap:Header>

  <soap:Body>

    <readMetadata xmlns="http://soap.sforce.com/2006/04/metadata">

      <type>Profile</type>

      <fullNames>Admin</fullNames>

    </readMetadata>

  </soap:Body>

</soap:Envelope>    Did Salesforce make any changes to profile read and edit security permissions in the last week?  Do I need to grant aditional access since last week? I don't what happens.    Thaks for your help!