To work under iis you need disable response buffer threshold:
Also the web.config is simpler:
<?xml version="1.0" encoding="UTF-8"?> <configuration> <system.webServer> <rewrite> <rules> <rule name="n8n" stopProcessing="true"> <match url=".*" /> <action type="Rewrite" url="http://127.0.0.1:5678/{R:0}" appendQueryString="true" logRewrittenUrl="false" /> <conditions> <add input="{HTTP_HOST}" pattern="^n8n.intranet.local$" /> </conditions> </rule> </rules> </rewrite> </system.webServer> </configuration>