Smart IPTV is removed from certain regions.
It's poosible to change the LG service country region to a different country that has the Smart IPTV app, install the app, then change the region back to your country.
I have the same problem. My list is gone and everytime that I try to put it, Smart IPTV told me the my app is empty.
I took Duplexplay like suggested, but there are nt subtitles.
I was so happy since the new version ot Smart IPTV supported all subtitles.