Bad Request


Your browser sent a request that this server could not understand.
Size of a request header field exceeds server limit.

Work around

Clear all cookies for this site and reload.

Cause

Apache has limited http header capacity. PHP (stupidly) tries to load all cookies every time it is invoked. It does this by forcing them all into a single http header.
The Robot's programs are passed to it via cookies. Normally the robot manages its cookies to ensure they work around this particular PHP stupidity but sometimes you may encounter this error.
The fix is to use your your browser to delete (cf. firefox Tools|Clear Private Data) suffient cookies for this site (e.g. all of them) so that the remainder fit into a single apache http header (about 8k bytes).

Improved Browsers

Apple Safari

Now (working!)
My thanks to Michael O'Neill for reporting this and for verifying the fix.

Konqueror

Now working!
My thanks to Peter Ross for reporting this.

Bad Browser

Blowing off steam (bad workmen blaming...)

Help with fixing this would be welcome.

Microsoft internet explorer 7

As of 27 July it is taking no notice of cookies created by PHP
My thanks to Martin Sewell for reporting this.

W.B.Langdon 29 June 2008 (last update 14 August 2008)