Date Initially Written: 19 September 2003.
Problem: Trying to open a FrontPage website in FrontPage 2000 results in an error: "The server sent a response which FrontPage could not parse."
Operating System: Windows 2000 Professional with service pack 3.
Background: I don't use FrontPage very often but I've still got a couple of old FP websites that I have to maintain. Everything has been working fine for ages until today I got the error message:
The server sent a response which FrontPage could not parse. If you are trying to connect to a FrontPage server, check with the server's administrator to make sure the FrontPage server extensions are installed properly.
It didn't matter which site I tried opening, I always received the same error. Note that I was just trying to open a local FP website, I wasn't trying to publish the site.
Resolution Steps: In an effort to fix this problem I ran the Detect and Repair option found under FP's Help menu. This didn't help at all; I still received the same error.
Some research on Google Groups showed that plenty of other people had encountered the same error and most of the suggestions were to do with reinstalling the FrontPage Extensions.
One message I read mentioned that this error can occur when the HTTP Keep-Alives option is not turned on in the IIS management console. I remembered that a week ago I had turned this option off because I was continually being told:
HTTP 403.9 - Access Forbidden: Too many users are connected
Internet Information Services
while I was working on a new site for a client and testing it on my local system. The reason I was getting this error was because I had HTTP Keep-Alives turned on. What is HTTP Keep-Alives? Well, when a browser first connects to a web server it establishes a "connection". That connection remains open until the browser disconnects or until the connection times out. The idea is that keeping the connection open will speed up subsequent requests to the server. The timeout duration can be set in the IIS management console (default is 900 seconds). Also in the IIS management console is a setting to enable HTTP Keep-Alives (enabled by default). All very well and good but under Windows 2000 Professional IIS is limited to ten simultaneous connections (Microsoft want you to upgrade to Windows 2000 Server to get unlimited connections). But you can make the most of those ten connections by disabling HTTP Keep-Alives or shortening the connection timeout duration. If you want availability to the highest number of users then disable HTTP Keep-Alives altogether. Keep in mind that this will require every request from a browser to reconnect to the server every time a HTTP request is made, thus slowing requests down a bit, but the connection will close after every request and therefore make that connection available to other users. This will degrade the overall performance for the user but it will allow IIS to service more users. Since I only run IIS for my internal use this isn't a problem.
It appears that FrontPage requires the HTTP Keep-Alives option to be enabled. Turning the option back on got my FrontPage working again. Here's where you find the HTTP Keep-Alives option:
After doing this I was worried that the Access Forbidden problem would return but so far it hasn't. I use the Opera browser for a lot of my testing while developing websites and it allows the user to specify how many connections to have open at once, so I may need to reduce this number if the Access Forbidden problem comes back.
Recommended Reading For FrontPage Users: FrontPage 2003 - The Missing Manual