Solution
Since the middle of June, 2015, a phenomenon has been seen where printer registration or printing cannot be performed in Google Cloud Print. It is due to change of the Google server’s authentication method.
Solution:
No measures are planned for the printer
To resolve the phenomenon, the printer firmware needs to be upgraded. However, the firmware upgrade cannot be performed due to the printer capabilities.
Workaround:
By connecting the printer to the internet using a PC, you can use Google Cloud Print without the phenomenon.
For details, visit Google Cloud Print home page, then go to "Cloud Ready Printers," "Add a Classic printer," and "Connect your classic printer."