mediaelementplayer-legacy - the Flash message is no longer needed.

[edent]

I don't think this message is still needed in 2026:

'mejs.install-flash' => __( 'You are using a browser that does not have Flash player enabled or installed. Please turn on your Flash player plugin or download the latest version from https://get.adobe.com/flashplayer/' ),

From: ​https://github.com/WordPress/wordpress-develop/blob/940e7a357729f7683a11658fc841a42711321a5e/src/wp-includes/script-loader.php#L1102

It is injected into my sites as part of <script id=mediaelement-core-js-before>

Following that link eventually goes to Adobe's FAQ about Flash which says:

Since Adobe no longer supports Flash Player after December 31, 2020 and blocked Flash content from running in Flash Player beginning January 12, 2021, Adobe strongly recommends all users immediately uninstall Flash Player to help protect their systems.

As far as I can tell, WordPress's MediaElement will never produce a SWF file for playback - so this error message will never be seen by users.

All occurrences should probably be removed ​https://github.com/search?q=repo%3AWordPress%2Fwordpress-develop+install-flash&type=code

Removes the obsolete mejs.install-flash localized string from the MediaElement.js mejsL10n object registered in wp_default_scripts(). This message told users to install/enable Adobe Flash Player, but Adobe ended support for Flash Player on December 31, 2020 and WordPress's MediaElement configuration never produces the SWF-based renderer that would trigger this message, so it can never actually be shown to a visitor. Removing it drops dead translated content from every page that enqueues mediaelement-core.

Added a PHPUnit test (Tests_Dependencies_Scripts::test_mediaelement_l10n_does_not_include_flash_message) asserting the inline mejsL10n script data registered for mediaelement-core no longer includes the mejs.install-flash key, while confirming sibling strings such as mejs.play are still present.

## Use of AI Tools

AI assistance: Yes
Tool(s): Claude Code
Model(s): Claude Sonnet 5
Used for: Implementation, tests, and PR description. Reviewed by Igor Rozum.

[westonruter]

Makes sense to me. This reduces the burden on translators

[mirmpro]

This sounds like a good Core cleanup.

[mirmpro]

Do we anticipate any regression risk from removing this string? As far as I can tell, the Flash fallback is no longer used, but I wanted to check if there are any remaining code paths or legacy integrations that might still depend on mejs.install-flash.

[westonruter]

The string is only used here:

​https://github.com/WordPress/wordpress-develop/blob/c5690fd7e8721f60f7c40db81debbbf149e87d68/src/js/_enqueues/vendor/mediaelement/mediaelement.js#L1751-L1765

So only on IE and Edge. I'm not sure if this refers to the legacy Edge or the Chromium Edge.

This may end up being made obsolete by upgrading ME.js to the latest version: #56320

So let's actually revisit this change later.