What's causing this?

[speedygonzales]

The sky is a mess.
Is this due to something I've done in processing?

 

[posiview]

What do you think is wrong with it?

Just looks empty to me

Cheers.

 

[speedygonzales]

Just checked this on another laptop and it looks fine! I think I have a problem with my monitor!

 

[Brian Sayle]

do you mean the vignetting? or some kind of pixel problem? have you done a lot of sharpening perhaps? there does seem to be a slight black glow around the fella on the bike