Please try below instructions in order to resolve this error.
Reinstall Netflix app:
1. Remove Netflix app
2. Reboot Roku
3. Re-install Netflix app.
Reduce your modems MTU size:
1- Launch a web browser from a computer or mobile device that is connected to your router's network.
2- Access router's Admin Page; Enter the router user name and password.
3- Select ADVANCED > Setup > WAN Setup.
4- In the MTU Size field, enter 1250.
5- Click the Apply button.
Register for an American Roku account:
- First, setup your VPN on your PC/Mac. This is a crucial step. Without it, Roku will flag your account as non-US.
- Now, head over to https://my.roku.com/index and choose ‘Create account’.
- Then, fill in the required information and then click ‘Continue’.
- Next, choose a Pin and click ‘Continue’.
- On the next page, you have to payment options: Paypal or Credit Card.
- If you already own a Paypal account use the Paypal payment option. Your Paypal country does not affect your Roku account.
- Use a valid US address to create your American Roku account. You can use California as your state and 90210 as your zip code.
- If you choose Credit card as your payment option, you have to use your own street address that is associated with your credit card.
- Then, you need to convert the postal code into a valid zip code.
- Keep note of the City associated with the new zip as it is required for the Roku account setup.
- To create a valid zip code, take the digits from your postcode. The postal code M1Z4L3 becomes 143. Add zeros to the end if you have less than 5 digits in your postal code. So the 143 becomes ZIP 14300.
- Now that you have finalized your Roku account, reset your Roku streaming device to factory settings. Then, use the newly created American Roku account on your Roku device.
ADD AMERICAN CHANNELS TO ROKU ULTRA OUTSIDE USA
Now that you have registered your US Roku account and used it to sign into your Roku Ultra, it’s time to add US channels like HBO Now, Hulu, Sling TV, and Amazon Prime.
- Press the ‘Home’ button on your remote to open the main screen.
- Scroll down and select ‘Streaming Channels’ to access the Channel Store.
- Search for the channel you wish to add.
- Once you find the channel, press ‘OK’ on your remote control.
- Finally, select ‘Add Channel’ to install the channel on your Roku device.
Check out solutions mentioned here: