From Day One, I've used a different weather app than the stock one that came with the S6 Edge. I just started receiving this error message several months ago and it was driving me insane! I tried everything except the factory reset, but nothing seemed to work. Then, I decided to go into the Weather app to see if I could uninstall it or disable it. In doing so, I found a fix that works:
1) In Settings, scroll down and select Applications to access the Default Applications screen.
2) Scroll down and select the Weather app.
3) Select Refresh and set it to None.
I haven't seen that error message since I did this, so I'm calling it a win! I hope it's a good solution for others, as well.