Unable to request a new clone even if correct username and password is provided.
After providing username and password, the error message "Destination returned error status = 500" is observed.
This issue can be caused by more than one issue:
The user requesting the clone does not have the clone_admin or soap_script role.
The system property glide.soap.require_ws_security is set to true.
Make sure that requesting user has the clone_admin or soap_script roles on source and target instance. Note that if the user has the admin and security_admin role, the user might not have the clone_admin or soap_script role so check for these roles explicitly.
Set the system property glide.soap.require_ws_security to false.
If user has all the correct roles and the system property is set to false but the issue still occurs, try clearing the browser cache and then requesting clone again.