Contact Form 7 6.2: "Composer detected issues in your platform" (PHP 8.3 required)

Composer detected issues in your platform:

Your Composer dependencies require a PHP version ">= 8.3.0".

Short answer: Contact Form 7 6.2 needs PHP 8.3 or newer, and on older PHP it stops the whole site with this error. Switch the site to PHP 8.3+ in your hosting panel, or put Contact Form 7 back to 6.1.7, the last version that runs on PHP 7.4. If the site is down, rename the plugin folder first to get it back.

Why it happens

Contact Form 7 6.2 (6 October 2026) and every release since, up to 6.2.4.1 on 29 October, declare "Requires PHP: 8.3" and "Requires at least: 7.1". They also ship Composer's platform check, which runs before any plugin code and throws a RuntimeException on PHP below 8.3. WordPress refuses an update only when the PHP doing the update is too old, so a site can still end up running 6.2 on old PHP: an auto-update or a WP-CLI/cron job run by a newer PHP binary, or a multisite child site or subdomain served by an older PHP handler. Version 6.1.7 needs only PHP 7.4 and has no Composer check. We reproduced it on 31 October 2026: loading 6.2.4.1 on PHP 8.2.12 printed exactly this error and stopped with exit code 255; on PHP 8.6.0RC4 it loaded normally.

You may also see

PHP Fatal error:  Uncaught RuntimeException: Composer detected issues in your platform: Your Composer dependencies require a PHP version ">= 8.3.0". You are running 8.2.12. in .../wp-content/plugins/contact-form-7/vendor/composer/platform_check.php:22

Fix

Site down (HTTP 500 or this message on every page)? Rename wp-content/plugins/contact-form-7 to contact-form-7-off with your host's file manager or FTP. WordPress deactivates it and the site comes back; your forms and messages stay in the database.
Check which PHP really serves the site: Tools → Site Health → Info → Server → PHP version. If your host shows 8.3 but this says lower, the domain or subsite uses another PHP setting. Change it there too.
Lasting fix: switch the site to PHP 8.3 or 8.4 in the hosting panel. First check your other plugins and theme; our free PHP Upgrade Readiness plugin lists what PHP 8.1 to 8.6 flag. Then rename the folder back to contact-form-7 and activate it.
Can't move off PHP 8.2 yet? Put back 6.1.7: download https://downloads.wordpress.org/plugin/contact-form-7.6.1.7.zip, delete the renamed folder, then Plugins → Add New → Upload Plugin and activate it. With WP-CLI: wp plugin install contact-form-7 --version=6.1.7 --force.
Stop it updating again until you are on PHP 8.3: Plugins → Contact Form 7 → Disable auto-updates, and skip the update notice.

Moving the site to PHP 8.3 anyway? Check every plugin and theme first. The free PHP Upgrade Readiness plugin lists the code PHP 8.1 to 8.6 flag, with file, line and fix, and sends nothing anywhere.

Download PHP Upgrade Readiness (free)

Which popular plugins log notices on PHP 8.6: our test of the top 100.

Watch out

Contact Form 7 6.2 also requires WordPress 7.1. On WordPress 7.0 or older, update WordPress first, or stay on 6.1.7.
Don't edit platform_check.php to skip the check. The plugin's code needs PHP 8.3 features, so it fails anyway, and the next update puts the check back.
6.1.7 gets no new fixes. Treat it as a bridge until the PHP 8.3 move.
Forum reports after 6.2.3 also describe forms that don't submit in some themes. That's a separate issue; we haven't tested it.

Sources

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