1. Check if your non-SSO password is correct set
  2. Double check if your internal application is active
  3. Verify whether private key is correct
  4. It might that application is not correctly created – i.e., it is not created as Internal application
  5. Try to generate token by your self using the following curl script:

    curl --request POST -H 'Content-Type: application/x-www-form-urlencoded' -H "Content-Type: application/json" -d grant_type=password -d username='admin_username' -d password='admin_password' -d client_id='your_client_key' -d client_secret='your_client_secret_key' -d scope='Egnyte.filesystem Egnyte.permission Egnyte.audit Egnyte.link Egnyte.user Egnyte.group' https://your_domain.egnyte.com/puboauth/token