.NET application runs on IIS 7 but not on IIS 7.5

A few years ago, I built a "front page" for my site, using CSS to implement a flexible column system (instead of fixed width). Works fine under IIS 7, but when I upgraded my web server to 2008 R2, the page content displays but no CSS activity is evident.

I brought in a couple pages from a simpler site that works in a different folder, and that works fine, proving that CSS can behave just fine.

I have compared the two pages, and the only differences are in the accompanying CSS code.

From serverfault Michael Broschat

• Since css is rendered by the browser my guess is that you have some sort of permissions issue. Are you able to download the css file directly using a link for the source of the page?

  So for instance, if in your page you have the following in the html source:

  <link rel="stylesheet" href="http://sstatic.net/sf/all.css"> 
  

  Are you able to go to http://sstatic.net/sf/all.css directly from the browser?

  Michael Broschat : Yes, it was a permissions issue. The original files were on one server that had lost its domain. When copied over to the new server (with a new domain), sufficient retention of permissions by non-existent accounts caused all sorts of difficulties. By changing permissions to current accounts, I eventually got the right ones in place. Thanks!
  From Kyle Brandt

• Use a HTTP debugging tool for your browser to check all the requests and if there is one failing (the one that shout fetch the CSS).

  I recommend the free tool "Fiddler."

  Michael Broschat : Good suggestion, and had the problem continued, I would have pursued this. I had invoked Fiddler from a client machine somewhere, but knew too little about it to gain much.
  From splattne