<p>For my website I configured some custom error pages.
If I generate a 404, the redirect works fine.
When hitting a 400, the "bad request" text shows up instead of the configured URl.</p>

<p>As a test I copied the URL from 404 to 400. No change.
Then I changed the redirect to a file. No change.</p>

<p>Any ideas?</p>

Check what's in your web.config file in the
```
customErrors
```
section. That has a
```
defaultRedirect
```
attribute, and an
```
error
```
subtag with a
```
redirect
```
attribute. These can conflict with your other configuration settings in IIS.