First I'd say is to reboot your phone. Then check that you haven't accidentally toggled "block pairing requests", then try removing the paired device from the tv AND the phone and then pair it again. Update your phones software, update smart things. Check that your tv and your phone are on the same wifi(you should still be able to smartview even if your tv has no data connection) i've found that you cannot connect to your tv if you are using a vpn on your phone. On some other versions of smart view there is three dots in the top right corner when tapped it says omething like "enable wireless display" try tapping this and then selecting your tv. If all this fails try connecting to bluetooth to your tv to see if it is able to connect. If it does then it might not be the tv. These are all the troubleshooting tips I know. I regularly connect to my offline samsung tv with my offline phone so I get to deal with these issues every once in a while. Good luck.
I'm sorry to her this about your Smartview. I think Atxzo has the right idea for troubleshooting your devices. Definitely want to check if you are on the same Wifi and make sure both devices are up to date. Make sure your phone is running Android 4.3 or above, and with devices that supports Miracast wireless. The last resort would be a Factory Reset; Make sure to back up your phone.
Navigate to Settings. Search for and select Factory data reset. Tap Factory data reset again, and then tap Reset. Follow the on-screen prompts to complete the reset. You may need to enter your Samsung account password or Lock screen password. The phone or tablet will reboot.
If you still require assistance, You can send us a private message so we can look into this.
