Thursday, September 29, 2016

Issues with IIS after Windows 10 Anniversary Update


After the Windows 10 Anniversary update was automatically installed, I noticed none of my local websites were working – instead giving me a 503 – Service Unavailable. Being a developer, and one that relies quite heavily upon IIS, this was deeply troubling.

Luckily, I saw this before after my Windows 7 to Windows 10 upgrade. If you see this issue, you may have experienced something similar.

Check IIS


First, I did the typical restart stuff, with the command-line IIS reset, and tried hitting the local website again, with the same result. In IIS, the application pool for the Default website had stopped.

Check Logs


Next, I looked in Event Viewer. In the Application Windows Logs, I saw this error:

The Module DLL C:\WINDOWS\system32\inetsrv\rewrite.dll failed to load.  The data is the error.

Once again, there was an issue with an IIS module – in this case, the URL Rewrite module.

Repair or Reinstall


In Control Panel –> Programs and Features, you can find the “IIS URL Rewrite Module 2” in the list of installed programs. You can either repair the module here, or uninstall and install again.
In my case, I chose the scorched earth approach, and uninstalled.

Now, you can re-install the module with Microsoft Web Platform Installer. A shortcut is conveniently located in the IIS manager, under Management. You can also find it in the Start menu. Search for “URL rewrite”, and the module will appear in the results. Select and install, then try again.

Try Again


I hit my local website, and voila! The website loaded successfully. (Note: You may have to reset IIS to take effect). Hope this helps.

Mark Doyle
Software Architect, Collabroscape
@mark_doyle_ftw