Welcome to the Roku Community, @sassybasslady!
Thanks for letting us know about your problem connecting the Roku Ultra to a wired ethernet. We're happy to help.
We recommend rebooting both your router and your Roku device. We would also recommend trying another ethernet cable.
The error code you mentioned is detailed in our Support resources here: What should I do if I can't connect to my home network or the Internet?
Please try doing this and see if it helps with what you're experiencing.
Best regards,
John
John
Roku Community Moderator