---
title: Changes in Web Agent 5.10.x
description: IIS agents use Windows libraries and ECMAScript-compatible regular expressions. Adapt the regular expression settings for IIS agents to account for this change.
component: web-agents
version: release-notes
page_id: web-agents::changes-510
canonical_url: https://docs.pingidentity.com/web-agents/release-notes/changes-510.html
section_ids:
  changed-in-510: Web Agent 5.10
  regular_expression_pattern_matching_is_platform_dependent: Regular expression pattern matching is platform-dependent
  fragment_redirect: Fragment redirect
---

# Changes in Web Agent 5.10.x

## Web Agent 5.10

### Regular expression pattern matching is platform-dependent

IIS agents use Windows libraries and [ECMAScript-compatible](https://en.cppreference.com/w/cpp/regex/ecmascript) regular expressions. Adapt the regular expression settings for IIS agents to account for this change.

### Fragment redirect

From Web Agent 5.8.1, when `Enable Fragment Redirect` is `true`, the agent redirects the user back to the original resource using an absolute URL. In previous Web Agent 5 versions, the agent redirects the user using a relative URI.

Proxy rules that rely on fragment redirect to a relative URI, now result in a redirect to a full URL. For example a redirect to `/a/b#c` results in the final URL `prot://host:port/a/b#c`.

Ordered rules that rely on matching a plain URL followed by fully qualified alternatives can result in the fully qualified alternatives matching first.