IIS 6: HTTP Compression Problem

Short Version

  • Error: Internet Explorer cannot display the webpage
  • Solution: Disable “HTTP Compression” in both Web extension and “Service” tab of Website properties

This short version is for those who are not interested about the details of this problem.

Long version

It took me almost 2 days to figure out about this issue so I’m going to share the details with you guys in this post. But as I didn’t use IIS 6 for long time and my main technical expertise is not IIS, the solution that I found might not be the best solution. If you guys know better solution for this issue, please feel free to share with us in comment section. Thanks!


Our server is Windows 2003 advanced server. We have .NET 1, .NET 2 and .NET 4 installed on that server. The existing website which is written in ASP.NET 2.0 is currently running on that server.


We got this issue when we tried deploying our new web application which is a hybrid app of ASP.NET 4.0 and ASP.NET MVC 3 on that server. To my surprise, ASP.NET MVC works great fine but ASP.NET 4.0 pages drove us crazy. I thought that the problem might come from the fact that our application is a hybrid so I created a brand new ASP.NET 4.0 application in Visual Studio 2010 and published it on the server but it didn’t work. It’s very weird because MVC project is working fine so .NET 4 framework shouldn’t have any problem but couldn’t figure out why ASP.NET 4.0 site wasn’t working.

In order to narrow down the problem, I created new Virtual Directory and new application pool and put a HTML page in that directory so we don’t need to worry about .NET issue. but this issue was getting more weird. Can you guess what happened? When I tried accessing that page from browser, it was working fine for the first time request but it didn’t work for second time request. I got different errors as below in different browsers.


Internet Explorer cannot display the webpage

Google Chrome

This web page is not available The web page at http://19x.10x.10x.2:17x/simpleweb/c.html might be temporarily down or it may have moved permanently to a new web address. Error 330 (net::ERR_CONTENT_DECODING_FAILED): Unknown error.


Content Encoding Error The page you are trying to view cannot be shown because it uses an invalid or unsupported form of compression. Please contact the website owners to inform them of this problem.

IE didn’t give any information as usual (well, we love IE! :P ) but when I saw the error message in Firefox, the encoding and gzip things came into my mind but I wasn’t so sure whether IIS server stopped responding the second request or the encoding issue. I looked at IIS log. As you can see below, IIS returns 200 so IIS wasn’t blocking the second request.

IIS log

#Software: Microsoft Internet Information Services 6.0
#Version: 1.0
#Date: 2011-12-14 06:27:57
#Fields: date time s-sitename s-ip cs-method cs-uri-stem cs-uri-query s-port cs-username c-ip cs(User-Agent) cs(Referer) sc-status sc-substatus sc-win32-status sc-bytes cs-bytes

2011-12-14 06:29:27 W3SVC1531730165 GET /simpleweb/d.html – 170 – Mozilla/4.0+(compatible;+MSIE+7.0;+Windows+NT+5.2;+.NET+CLR+1.1.4322;+.NET+CLR+2.0.50727;+.NET4.0C;+.NET4.0E) – 200 0 0 378 284

Just to make it more sure, I used Fiddler to capture the traffic between the browser and server. I managed to get the response but when I viewed the response stream, I got this error below in Fiddler.

Fiddler: UnGZip failed
The content could not be decompressed.
The magic number in GZip header is not correct. Make sure you are passing in a GZip stream.


As Fiddler showed that there is something wrong with gzip, I decided to turn off the HTTP compression on that server.

How to turn off the HTTP compression on IIS 6? It’s pretty simple. Go to the properties of Website (not virtual directory or application) and uncheck “Compress application files” and “Compress static files” on “Service” tab. And set “Prohibit” to “HTTP Compression” in Web extension.

Note that I tested HTTP compression on fresh 2003 server and it works so I think gzip assembly got some problems on that server only. That’s why I mentioned that disabling HTTP compression might not be the best solution but we decided to stop experimenting it for now because we are using 2003 server temporarily. I don’t think it’s good idea to host ASP.NET 4 app and MVP app on IIS 6 so we are going to get new Windows 2008 R2 service with IIS 7 later.. But yeah. if you have a better solution then please share with us.

Credits: Thank you all to everyone who gave a lot of suggestions for this issue. You guys helped me a lot. Thanks! 

Nuget Update Error

Yap. It’s happening again with Nuget Update. I got new update for nuget this morning but I kept on getting error when I update it. When I check the log, I found that it’s the same issue that we had a few months back. I’m not sure how many times we are going to face this issue in future so I’m just sharing it with you guys in case you have the same problem.

Error Logs

16/12/2011 9:38:25 AM – Verifying matching extension signatures before updating…
Installed Extension Path: C:\Program Files (x86)\Microsoft Visual Studio 10.0\Common7\IDE\Extensions\Microsoft Corporation\NuGet Package Manager\1.5.20902.9026\
Update Extension Path: c:\users\michael.sync\appdata\local\temp\tmp479e.tmp
16/12/2011 9:38:25 AM – VSIXInstaller.SignatureMismatchException: The signature on the update version of ‘NuGet Package Manager’ does not match the signature on the installed version. Therefore, Extension Manager cannot install the update.
at VSIXInstaller.Common.VerifyMatchingExtensionSignatures(IInstalledExtension installedExtension, IInstallableExtension updateExtension)
at VSIXInstaller.InstallProgressPage.BeginInstallVSIX(SupportedVSSKU targetAppID)
16/12/2011 9:38:25 AM – Install Error : VSIXInstaller.SignatureMismatchException: The signature on the update version of ‘NuGet Package Manager’ does not match the signature on the installed version. Therefore, Extension Manager cannot install the update.
at VSIXInstaller.Common.VerifyMatchingExtensionSignatures(IInstalledExtension installedExtension, IInstallableExtension updateExtension)
at VSIXInstaller.InstallProgressPage.BeginInstallVSIX(SupportedVSSKU targetAppID)


  • Open Visual Studio 2010 with administrator right (You need this. Otherwise, the “Uninstall” button on Nuget will be disabled. )
  • Remove Nuget from Visual Studio 2011 first
  • And install it again from online gallery
That’s it!

Blend 4 + VS 2011 (Preview) = Problem?


Microsoft Expression Blend 4 crash on startup after installing Visual Studio 2011 Developer Preview on my machine..


I found this bug report in MS Connect.  Christopher Cole from Microsoft Expression responded that report with the solution below.

There is a compatibility problem with .Net 4.5 installed as part of the Developer Preview and Blend 4. This issue was fixed, but too late to make the preview build.

The workaround is to run:

%windir%\Microsoft.NET\Framework\v4.0.30319\ngen uninstall “%ProgramFiles(x86)%\Microsoft Expression\Blend 4\Microsoft.Expression.Framework.dll”
%windir%\Microsoft.NET\Framework\v4.0.30319\ngen uninstall “%ProgramFiles(x86)%\Microsoft Expression\Blend 4\Microsoft.Expression.Blend.dll”
%windir%\Microsoft.NET\Framework\v4.0.30319\ngen uninstall “%ProgramFiles(x86)%\Microsoft Expression\Blend 4\Microsoft.Expression.Project.dll”

If “%ProgramFiles(x86)%\Microsoft Expression\Blend 4\Microsoft.Expression.WindowsPhone.dll” is present (for scenarios like Blend V4 SP1 or future releases), please also run:
%windir%\Microsoft.NET\Framework\v4.0.30319\ngen uninstall “%ProgramFiles(x86)%\Microsoft Expression\Blend 4\Microsoft.Expression.WindowsPhone.dll”

I just tried it on my machine and it works for me so I’m sharing it with my readers here..


Error: Unrecognized option Files

You have integrated Git with Command Prompt, you will get this error when you run “ngen”. If you happen to have the older preview version of git, you will get the error below when you try to uninstall it. I had to delete the git folder manually.

Runtime Error (at 18:1292):

Could not call proc.



Tip for Windows Phone Wi-Fi issue

I’ve been using HTC Mozart Windows Phone for a few months and I’m quite happy with that phone. 

Unfortunately, I got an issue after updating latest version of Mango yesterday. I was using the early version of Mango as well. I didn’t have any problem until yesterday. The problem is that I couldn’t able to detect my wi-fi network from my phone. I tried quite a few way to fix that issue. I even did the hard-reset for my phone but didn’t work. My friend suggested me to change the wireless channel of my router. Finally, the trick did work. So, I’m just sharing what I found here. Hopefully, it would help someone.. :)

HTC 7 Mozart – C1010009 in updating Windows Phone 7.1 (Mango)

My phone “HTC 7 Mozart” was having problem in updating Windows 7.1 Mango “7.10 (7720)”. I kept on getting “C1010009” error whenever I tried to update.

After doing some researches and googling a bit, I came to know that it’s because of the USB port. I was using the USB ports which are in front of the system box . So, I switched my phone USB cable to the port at the back of my system box then it works.

If you are also having C1010009 error, please try switching different USB port and try updating again. Please feel free to share if you have any other solution!

Encoding MP4 Problem in Expression Encoder 4 Pro

I wanna tell you guys about one problem that I’m facing with Expression Encoder 4 Pro. Do you guys ever see this error “This functionality is only available in the fully-featured Expression Encoder Pro” while you are using Expression Studio Ultimate licensed version?  I heard that the most of users who are using the MSDN subscription version of Expression Studio are having this problem.  When you change the Output Format “Windows Media” to MP4, you will get this error.

The screenshot of that error is as below..

I think Microsoft is aware of this issue and I hope we will get the fixes very soon.. Emily Anderson from Microsoft wrote below in IIS7Media forum ~

Thanks for your interest in Expression Encoder.  We have two version of Expression Encoder 4: The first is included in Expression Ultimate purchased through volume licensing, MSDN, and Bizspark, and does not include royalty-bearing codecs.  The second version is included in Expression Ultimate purchased through retail channels, and does include the codecs. The reason for needing two product versions is due to codec redistribution and reporting requirements. Unfortunately we’ve experienced some technical issues with MS store, but we expect the problems to be resolved in the next 48 hours and Encoder to be available again before the end of the week.

If you are wondering whether you have the same problem or not, you can go and check the AboutPage of Encoder 4. The following is mine. If you have “(without codecs)” then you will probably have the same problem..  The only solution that I know is to wait a few more days to get the latest version of Encoder 4 from MSDN subscription. Let me know if you know other workaround..