first downloading the incremental wyu file but then downloads the all to x wyu too why?

hi,

I am testing my update. It updates the software but when i checked fiddler i see that.

it downloads 2 wyu file ...

1.1.to.1.2 andall.to.1.2

what can cause this?

The only cause for this is a file failed to patch. But this is a good question, that's asked so often that we've bitten the bullet and written a FAQ entry for it. See: What's the "catch-all" update? Why is it so large? And why is it being downloaded?