Flickering image blocks - any ideas
 

Only on the external view... any ideas.
https://i.imgur.com/PYkZMWp.jpeg

Lens flare?
 

Is it a lens flare effect not working properly? Looks like something applied to the sky using an overlay texture but the texture is lacking an alpha component or the overlay method is not supported. Is it OK on a cloudy day and at night?
Try messing with all those horrible incomprehensible settings a couple of menus down on your graphics card. Or set the rendering preset to "quality". Or set it to "performance".

Found the Fog mods a possible cause.
Removed those and all is well again.

Hooston:- I'll keep an eye on that. thanks

:Kaleun_Thumbs_Up:
Fog makes sense. It looks like the sort of thing you get when two meshes are drawn in the same place in 3d space and I think fog mods tend to use semi-transparent mask objects. There are much cleaner and more efficient ways of doing fog, but probably much harder to insert into the ancient game code. Increasing the precision ("quality" on your graphics card settings) should fix it as it obviously worked for someone.
i noticed some of the ship models in GWX Knights Cross flickered a bit, which might be the same thing, it's easy to accidentally duplicate some polygons... But could be something else... :hmmm: