SeaMonkey 2.53.1

This version makes changes to your profile that can't be reverted in case you want to go back to a previous version of SeaMonkey. You MUST absolutely do a full backup of your profile before trying SeaMonkey 2.53.1. Automatic upgrades from previous versions are disabled for this release. Please download the full installer from the downloads section and install SeaMonkey 2.53.1 manually over the previous version.

The Mozilla backend code SeaMonkey is based on, now usually incorporates breaking changes in every release. This is especially true for the Mozilla Gecko add-ons code and the JavaScript interpreter. Consequently, some older extensions may no longer function properly. If you experience any problems please refer to the troubleshooting section first. Especially try to disable extensions first and check if this makes a difference.

Due to changes in the user profile, if you have set a master password, you will have to remove it before upgrading to SeaMonkey 2.53.1. After a successful upgrade, don't forget to manually remove the files key3.db and cert8.db in your profile afterwards, as they include credentials and passwords no longer protected by a master password. You can find the path to your profile folder entering the special about:support URL in a SeaMonkey browser window.

You can remove your master password by providing an empty password in the "Change Master Password" dialog. Do not use the "Reset Password" function. You will lose all stored passwords this way.

For SeaMonkey 2.53.1, the following extensions are included. ChatZilla

DOM Inspector

Lightning Beta versions also contain the following extension. SeaMonkey Debug and QA UI Beta versions also contain the following extension.

These release notes describe system requirements, installation instructions, and known issues for SeaMonkey 2.53.1 up to/including SeaMonkey 2.53.1. These notes are updated when we receive feedback, so please check back for new information.

What's New in SeaMonkey 2.53.1

SeaMonkey 2.53.1 contains (among other changes) the following major changes relative to SeaMonkey 2.49.5: The Bookmarks Manager has switched its name to Library, and now also includes the History list. When invoking History, the Library will be shown with the History list selected. The extensive modifications were needed because of Mozilla Gecko platform API changes.

Download Manager has been migrated to a new API. Although it looks pretty much the same as before, the search option is missing and some other minor details work differently. The previous downloads history is removed during the upgrade.

Added Layout panel to CSS Grid tools.

TLS 1.3 is the default version now.

The only NPAPI plugin which will work with SeaMonkey 2.53.1 is Flash. Support for other NPAPI plugins like Java and Silverlight has been removed. SeaMonkey 2.53.1 uses the same backend as Firefox and contains the relevant Firefox 60.3 security fixes. SeaMonkey 2.53.1 shares most parts of the mail and news code with Thunderbird. Please read the Thunderbird 60.0 release notes for specific changes and security fixes in this release. Additional important security fixes up to Current Firefox 72 and a few enhancements have been backported. We will continue to enhance SeaMonkey security in subsequent 2.53 beta and release versions as fast as we are able to. SeaMonkey-specific changes Among the general platform and mail fixes this release contains backported fixes from Thunderbird for the EFAIL security vulnerability.

SeaMonkey now uses gtk3 on Linux. If you experience a problem because of this please file a bug and link it to Switch Linux builds to GTK3 with SeaMonkey 2.49. Please try another OS theme first. Some of them are buggy and cause problems with SeaMonkey, Thunderbird and Firefox.

Downloading

The SeaMonkey project provides official versions and language packs of SeaMonkey 2.53.1 for Windows, Linux and macOS in US English and a small variety of other languages. Community volunteers are also contributing builds for other platforms. You can download SeaMonkey 2.53.1 here

System Requirements, Installation and Uninstallation



Please note that the new Windows x64 version will only support Windows 7 x64 and up. You need to uninstall a previous Windows x86 version if you want to use it. Installing the x64 over the old x86 is not supported and does not remove the old version which might cause problems later.

SeaMonkey 2.53.1 will no longer offer to migrate your data from SeaMonkey 1.x or Mozilla 1.x at the first start after installation (

If you are on an older release we suggest upgrading to SeaMonkey 2.49.5 first You can find more details about installation, profile data and uninstallation in our Before installing, make sure your computer meets the system requirements Please note that the new Windows x64 version will only support Windows 7 x64 and up. You need to uninstall a previous Windows x86 version if you want to use it. Installing the x64 over the old x86 is not supported and does not remove the old version which might cause problems later.SeaMonkey 2.53.1 will no longer offer to migrate your data from SeaMonkey 1.x or Mozilla 1.x at the first start after installation ( bug 689437 ). In order to upgrade from such an old version, install the last SeaMonkey 2.0 release first, do the one-time profile upgrade, uninstall SeaMonkey 2.0 and then install your target release (e.g. this one).You can find more details about installation, profile data and uninstallation in our install and uninstall document.

Extensions (Add-ons) and Themes