it seems like that you did not setup the security on your router properly or you are typing the wrong password. that's why you are having this kind of problem. so in this situation, you have to make sure about these steps.
Go to the settings on your device and then you need to click on wireless settings.
Now you will able see your WiFi name. so have simply need to click on your WiFi name and then you need to type your password in and click on ok.
Your netflix will be connected to the wifi.
You need to make sure, you are typing the correct wifi password on device. if you have wps facilitie on your device then you need to try to connect your device using wps. if it is still not connecting then you need to update your firmware.