Help identifying weird sky artifact

[Tonycubed2]

See that long darker line going thru the player and keeps on going? There are various number of them moving across like they were clouds. but they are not clouds as far as I know. I disabled all weather mods and it is still there. What could be doing this?? When using the world map it is visible there as well...

 

[URL=https://imageshack.com/i/pmUf2iJap][IMG]https://imagizer.imageshack.com/v2/1024x768q70/922/Uf2iJa.png[/IMG][/URL]

 

[z929669]

Are you using ENB? If so, try Shift+F12 to disable it and see if it goes away. If you use a sky mesh replacer or 'fog' mod, you could try disabling those.