IE7 HTTP Error 400

Question

Why would IE 7 display HTTP Error "Bad request" 400 on the same page that Firefox loads without complaining?

Answer 1

The server probably rejects the request issued by IE. It can be server problem or IE problem. However I doubt any help is possible without being more specific about the problem.

Answer 2

There are a number of things to try to troubleshoot what's going on:

1) Take a look at the server logs. Since a 400 error is usually caused by bad or invalid data coming in from the client, the server may be logging the error to its logs.

2) Run Firefox and IE7 through a proxy such as Charles and take a look at what's different between the two browsers' requests

Answer 3

Perhaps you're experiencing an IE7 bug involving javascript?

It doesn't exactly fit your description, but it was IE specific, and quite a pain to track down.

Answer 4

When you get a message like this turn off friendly HTTP error messages in IE. To do this go to Tools -> Internet Options -> Advanced. Uncheck show friendly HTTP error messages. Once you have done this you should get a more detailed message which will point you to the real problem.

Do you have a URL that you could share to further diagnose the problem?

Answer 5

If you have firebug installed (in firefox), look at the Net tab and see if a 400 header isnt getting passed back.

Answer 6

Install Fiddler2 and see EXACTLY what IE is sending/receiving from the server.

Answer 7

Also, IE replaces/used to replace backslashes ("\") for forward slashes ("/") in the URL - does the server script maybe use backslashes in URL as special characters?