Except where noted, everything here applies to both Firefox 85 and the Firefox 78.7 ESR.

Bug fixes

• Firefox no longer sets itself as the default PDF viewer on Windows 7. This was fixed in bug 1652412.

• If a website was blocked via policy, the website could still be downloaded via "Save Link As". This was fixed in bug 1680095.

• In some cases, Firefox said updates were available when they were not. This was fixed in bug 1599590.

• Extensions using identity.launchWebAuthFlow may now use a specifically formatted loopback address as the redirect URL. This was fixed in bug 1635344. More information is available here.

Policies

• Adding a theme via the ExtensionSettings policy now makes it the active theme. If there is more than one theme, the last one in the list is set. This only happens when the theme is first installed.