My ASPX website has CSS files and JS files linked as ASHX files. So for example I got
IsPostBack = false
IsCallback = false
Ok I found out what it was caused by: My web.config contained
<customErrors mode="On" redirectMode="ResponseRedirect"> <error statusCode="404" redirect="/" /> </customErrors>
<system.webServer> <httpErrors errorMode="Custom"> <remove statusCode="404" /> <error statusCode="404" path="/" responseMode="Redirect" /> </httpErrors> </system.webServer>
I know that's the wrong way to handle 404 responses, but I was not on the way to leave it. I just wonder why Chrome gets a 404 response, even when my handler returns content? Because this is the only reason how it could forward to "/" and repeat my life cycle.