Users can’t view PDFs from your Win Server 2008 R2 installation?


Another quick fix post for the day: In Windows 2008 R2 running IIS 7.5 an odd issue occurs when trying to view a PDF in Adobe Acrobat’s browser add-on. There appears to be a bug in Acrobat’s adherence to the RFC conventions, stopping your users from viewing PDFs in their browsers, and both sides’ responses are vague as hell. I’ll help you wade through the crap and get a working solution.

FrustrationAhead The Problem

If you have a web server running Windows Server 2008 R2 you may experience a weird issue, that you may not even be aware of. For all you know your users are having issues and you don’t even know – These are the worst kinds of problems. When they click on a link on your site to a PDF they won’t be able to “view” it in their browsers – sometimes it may actually crash their browser.

Windows Server 2008 R2 comes with IIS 7.5, which i have to say from experience is the best IIS yet. One of the little known upgrades to IIS 7.5 is that, while complying with the RFC standard, it supports sending multi-byte ranges in the place of a single-byte range, if the requested single-byte ranges can be sent as one multi-byte range. While this sounds complicated it is with the best intentions and means that your requests are completed faster and use less server resources.

Adobe Acrobat’s browser add-ons don’t fully support this though. So your users won’t be able to view your PDFs in their browsers properly. Really wish the world was using FoxIt Reader, like you now don’t ya?

So to be straight: by the letter of the law, IIS 7.5 is doing the right thing – it’s abiding by the RFC standard. Adobe Isn’t.

But this doesn’t solve our problem!

Correct! That’s why we’re here. Although adobe has stated that they have a fix “in the works” this doesn’t really help us with all the legacy version of Adobe Acrobat out in the wild. There is a really long forum discussion on this very issue here, but you don’t need to read pages of drivel, so lets solve this problem once and for all.

The Solution

So Microsoft has released a patch to “fix” the issue – by reverting this addition. Let’s be clear here: This is not the best solution. This is a quick fix to get your users happy again – and more importantly (maybe not to some but i think so) it will get you back on track, fixing more serious issues. But in the long term, if you can put it back the way it should  be, all will be better in the world.

View the patch information here:

Request a download of the patch: