500 error for long url iis7

Question

I was getting 404 errors for some long URLs on a website I'm developing. After a bit of digging I discovered that this occurs when the length of certain aspects of the URL exceed configurable limits in IIS7. In this case the maxQueryString attribute of the requestLimits property needed to be increased in the web.config

<system.webServer>
<security>
  <requestFiltering>
    <requestLimits maxQueryString="4096" maxAllowedContentLength="4096" maxUrl="8192" >
    </requestLimits>
  </requestFiltering>
</security>

This fixed the problem instantly on my development server but on the remote server I now get:

500 - Internal server error.

There is a problem with the resource you are looking for, and it cannot be displayed.

And that's all the information it gives me.

Answer 1

You should not use such long URLs. Among other reasons, at least one of the common toolbars (Bing, Yahoo, Google) will break them, producing just such errors. Users will blame you.

I know this because one of my users was having just such a problem with a legacy app. When I removed the toolbars (she had all three installed!), the problem went away.

Answer 2

Are you sure your hoster/production-server is running Windows Server 2008 (or 2008 R2)? The settings you are describing above are only valid for IIS 7+.

Answer 3

Change your Flash to send the data as POST, so it won't be appended to the URL. Here's some sample code. Also, you may need to change the server side to look for the data as POST instead of GET.