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Firefox Release Notes

Release Notes tell you what’s new in Firefox. As always, we welcome your feedback. You can also file a bug in Bugzilla or see the system requirements of this release.

66.0.4 Firefox Release

May 5, 2019

Version 66.0.4, first offered to Release channel users on May 5, 2019

Fixed

Unresolved

  • A small number of add-ons may be listed as unsupported or may not appear in about:addons. Their data is not lost; users should be able to re-install the add-ons and recover the data (Bug 1549129). More support information

  • If add-ons that use Containers functionality (such as Multi-Account Containers and Facebook Container) were disabled as part of this problem, any lost site data or custom configurations for those add-ons will not be recovered by this release. Users may need to set them up and login again in about:addons (Bug 1549204). More support information

  • Themes may not be re-enabled. Users may need to re-enable them in about:addons (Bug 1549022). More support information

  • Home page or search settings customized by an add-on may be reset to defaults. Users may need to customize them again in about:preferences or about:addons (Bug 1549192). More support information

  • Users with a master password set may need to enter or reset it for the fix in this release to take effect (bug 1549249). More support information

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