Can't add new OPTA to Arduino Cloud

[smmsadmin]

Thanks for your reply.

Here is my step:

1. Open the Arduino IDE, then click “New Sketch.”
2. Verify that the OPTA is connected via USB.
3. In the Arduino IDE, click “Upload,” and see the following messages

Download done.
File downloaded successfully
Transitioning to dfuMANIFEST state

4. Then add the OPTA with the empty sketch to the Arduino Cloud
5. Still shows the error messages in Chrome