Basic 404 prevention iRule not working in IE (Firefox fine)

So, I kind of doubt the iRule itself is having problems with IE vs FF, as it probably knows nothing about which one it is. My guess is IE might just be handling the response slightly differently.

 

 

I ran into an issue with that a little while ago. I was trying to have the iRule return a custom 404 error message if the user tried going to a path that we wanted to block. Firefox would display the contents I sent back just fine, but IE refused to and instead just showed its default 404 page (despite the fact that IE and FF were getting exactly the same data back). I never did figure out why. Your problem is probably different in that you're using a 200 response, but maybe the formatting of the response is something that IE doesn't quite like.

 

 

EDIT: I'm a moron and forgot you already posted the rule.