Except where noted, everything here applies to both Firefox 79 and the Firefox 78.1 ESR.

Bug fixes

• In some cases, PEM files failed to import if there was extra data in the file. This was fixed in bug 1642789.

• When Pocket was disabled, there was still an option to view Pages Saved to Pocket on the new tab page. This was fixed in bug 1639980.

• Even if permissions were locked by policy, they could still be updated by the user in the Page info dialog. This was fixed in bug 1630884.

• If the RequestedLocales policy was used to set a default language, the user couldn't change to a different language. This was fixed in bug 1592658.

• For the ESR only, JNLP files are not treated as executable, so they don't show additional warnings when launched.

• In previous versions of Firefox, disabling sync or overriding the first run page removed the onboarding messages from the new tab page. This was fixed in bug 1651093.

Policies

• Previously policy could disable the primary password but not force a primary password. This has been added with the new PrimaryPassword policy. The user will only be asked to create a primary password the first time they try to save a password.

• The Cookies policy has been updated to allow you to specify domains where cookies are only allowed for the current session.

• The media.peerconnection.ice.obfuscate_host_addresses.whitelist preference in the Preferences policy has been renamed to media.peerconnection.ice.obfuscate_host_addresses.blocklist.

Special Notes

• As mentioned in previous release notes, Firefox 78 is the last major release with support for macOS versions 10.9, 10.10 and 10.11. Users of these macOS versions will be supported through Firefox ESR 78.x for the coming year. You can read more about this here.

• The next ESR based on Firefox 68 (68.12) which will be released August 25, 2020 will be the last Firefox 68 based ESR unless there is a security issue before September 22, 2020. Users of Firefox 68 ESR will start to be automatically upgraded to the Firefox 78 ESR when Firefox ESR 78.3 is released on September 22, 2020.