---
title: Limitations
description: The following limitations are inherent to the design, not bugs to be fixed.
component: web-agents
version: release-notes
page_id: web-agents::limitations
canonical_url: https://docs.pingidentity.com/web-agents/release-notes/limitations.html
section_ids:
  custom_login_redirection_mode: Custom login redirection mode
  ignore_path_info_properties: Ignore path info properties
  iis_web_agent_installation: IIS Web Agent installation
  locked_iis_configuration: Locked IIS configuration
  installation_order: Installation order
  iis_web_agent_with_client_based_sessions: IIS Web Agent with client-based sessions
  apache_http_server_authentication_functionality: Apache HTTP server authentication functionality
  custom_error_pages_not_showing_after_upgrade: Custom error pages not showing after upgrade
---

# Limitations

The following limitations are inherent to the design, not bugs to be fixed.

## Custom login redirection mode

Redirect of users to a specific AM instance, an AM site, or website other than AM. Learn more in [Login redirect](https://docs.pingidentity.com/web-agents/2025.11/user-guide/login-redirect.html).

## Ignore path info properties

The NGINX Plus web agent doesn't support the following ignore path info properties:

* `com.sun.identity.agents.config.ignore.path.info`

* `com.sun.identity.agents.config.ignore.path.info.for.not.enforced.list`

## IIS Web Agent installation

### Locked IIS configuration

Installing web agents in IIS may fail with an error similar to the following:

```none
Creating configuration...
Error: failed to create module entry for MACHINE/WEBROOT/APPHOST/AgentSite/ (error 0x80070021, line: 1823).
The process cannot access the file because another process has locked a portion of the file. (error: 0x21).
Installation failed.
```

This error message means the `agentadmin.exe` command can't access some IIS configuration files because they're locked.

To work around this issue, perform the following steps:

1. Open the IIS Manager and select the Configuration Editor.

2. Unlock the IIS `system.webServer/modules` module.

3. Retry the web agent installation.

|   |                                                                                                                                                                       |
| - | --------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
|   | Unlocking the `system.webServer/modules` module should allow the installation to finish. However, you may need to unlock other modules depending on your environment. |

### Installation order

In an IIS environment where you need to protect a parent application and a child application with different web agent configurations, you must install the web agent on the child application before installing the web agent in the parent. Trying to install a web agent on a child that is already protected will result in error.

## IIS Web Agent with client-based sessions

IIS web agents configured for client-based sessions will return HTTP 403 errors when trying to access a protected resource if `com.sun.identity.client.notification.url` is configured.

The `com.sun.identity.client.notification.url` property was removed in an earlier unsupported release. Earlier versions of Web Agent use it to specify the notification listener for the agent. However, to provide backwards-compatibility with earlier versions of the agents, AM populates this property when creating the agent profile.

The value of this property should be removed for all agent installations, and must be removed for IIS web agents configured for client-based sessions.

## Apache HTTP server authentication functionality

The web agent replaces authentication functionality provided by Apache, for example, the `mod_auth_*` modules. Integration with built-in Apache httpd authentication directives, such as `AuthName`, `FilesMatch`, and `Require` isn't supported.

## Custom error pages not showing after upgrade

After upgrading, you may see the default Apache welcome pages instead of custom error pages defined by the Apache `ErrorDocument` directive.

If you encounter this issue, check your Apache `ErrorDocument` configuration. If the custom error pages aren't in the document root of the Apache HTTP Server, you should enclose the `ErrorDocument` directives in `Directory` elements. For example:

```none
<Directory "/web/docs">
  ErrorDocument 403 myCustom403Error.html
</Directory>
```

Read the Apache documentation for more details on the `ErrorDocument` directive.