When did you install SIPTV (smart iptv) app on your device ? Probably 7 day trial period is over? If so, then just buy the app on apps website
Well, I have the same problem. Kinda.
I had the app on my TV, but I've deleted it after my subscription ended. Now, I've downloaded it again but every time I try to insert my Playlist or buy the app it says incorrect MAC. It worked perfectly before.