IE scrambles script in IIS7 with static compression turned on

Question

I am having issues with javascript files not decompressing in IIS7 and stylesheets not loading properly.

I can fix this issue by turning off Static compression in II

Answer 1

This is qZip decompression fail. Can happen if the Content-Length on the header is not the correct one.

Some times if the page set the Content-Length on the header, and then the web server try to gZip the page, but fail to change the Content-Length - because have been all ready send to the browser.

Possible solutions is to remove the set of Content-Length from your code and let IIS set it, see if you all ready make qZip this files and decide - ether let iis do it for you, ether do it your self.

Similar problem and answer:
ASP.NET site sometimes freezing up and/or showing odd text at top of the page while loading, on load balanced servers

HTTP Compression: Some external scripts/CSS not decompressing properly some of the time

IIS content-type wrong for compressed CSS

Answer 2

I have narrowed this issue down to the web site using Blowery HttpCompression.

It seems that with .net 4.5 Blowery and IIS no longer play together nicely and the static content seems to be compressed twice, once by Blowery and once by IIS.

The above is a guess but one think I do know is that be removing Blowery the website works fine again.