I have a Custom 404 page written in classic ASP that's worked well for a couple of years. Suddenly, instead of seeing he expected nice 404, instead we're seeing a 500- internal server error.
There's nothing been changed in the IIS config (not deliberately, anyway).
Is this just IIS having a tantrum, running out of something? Might a restart fix it? Or is this a sign of something more serious?
IIS 7.5 on Windows 2008 R2.
At Nathan C's instigation, I've remote desktopped to the server and run this locally, and I get a more detailed error response. Top tip, by the way: didn't realise you could get a different result locally!
It seems to be saying that there's something wrong with the config.
I have two custom error pages, one for 404 and one for 410.
The 410 one works fine.
The detailed error response seems to be somehow confusing the two:
Cannot add duplicate collection entry of type 'error' with combined key attributes 'statusCode, subStatusCode' respectively set to 410,-1.
I've looked in the web.config and the errors section contains:
<httpErrors errorMode="Custom"> <remove statusCode="404" subStatusCode="-1" /> <error statusCode="410" path="/custom410.asp" responseMode="ExecuteURL" /> <error statusCode="404" path="/custom404.asp" responseMode="ExecuteURL" /> </httpErrors>
It strikes me that something is wrong with that page. It references the 404 twice but the 410 only once; there's either something extra or something missing.
But I'm not sure how it's meant to look.