Trying to watch Prime on Samsung tv Amazon app, and getting error code 1066, never had a problem before ....??
Hello Linda57 and welcome to the forum!
Let's try deregistering your Samsung TV.
1. Go to the website www.amazon.com/pin 2. Login with username and password for account where your device is registered. 3. Go to the section "Your Devices" and click on "Deregister" next to your Samsung. 4. Click "Deregister" on pop-up.
After completing those steps, restart your television and load Prime Video again - you should be prompted to login/register.