Im having exactly the same problem with my MIM-H03 device ( my interface for A/C multisplit) .
My issue started with a offline device and then o tríed to reset the conection . When i tríed the registration again, the smarthings app cant register my device and the proccess cant finish .
Hello,
I am writing to ask if your problem with registering your air conditioner has now been resolved.
I live in France and I have the same registration incident as you (31-164) for the same model of air conditioner.
If your incident is resolved, can you please tell me the solution implemented ?
I thank you in advance for your response.