PHP 8.1 / 8.2 Warnings After Upgrade

To fix PHP 8.1 or 8.2 deprecation warnings that mention Slugs Manager: Delete Old Permalinks from WordPress Database, update the plugin at Plugins > Installed Plugins. The PHP 8.2 “dynamic property” notice was fixed in version 2.6.5. Then update your other plugins and theme, and log notices instead of displaying them.

Symptoms #

• Notices such as “Deprecated: Creation of dynamic property … is deprecated” or similar PHP 8.x messages.
• Warnings appearing in wp-admin or logged to wp-content/debug.log.

Cause #

PHP 8.x deprecated some older coding patterns. When any plugin or theme still uses them, PHP emits a notice. These are notices, not fatal errors, and are usually resolved by keeping software up to date.

For Slugs Manager specifically, the PHP 8.2 notice “Creation of dynamic property is deprecated” was fixed in version 2.6.5. If you see it from Slugs Manager, your copy is older than that.

Check whether the notice comes from Slugs Manager #

1. Read the file path at the end of the notice. Slugs Manager files are in a wp-content/plugins/ folder whose name starts with remove-old-slugs (for example remove-old-slugs for the free version), and the main file is remove-old-slugs.php or remove-old-slugs-pro.php.
2. If the path points to another plugin or your theme, update or contact that developer instead.
3. Check your installed version under Plugins > Installed Plugins. Anything from 2.6.5 onward includes the PHP 8.2 fix.

Fix #

1. Update Slugs Manager. Go to Plugins > Installed Plugins and update to the latest version. Newer releases target PHP 8 compatibility, so updating is the first and most effective step.
2. Update everything else too. A notice referencing shared code can come from another plugin or the theme. Update all plugins and your theme, and confirm WordPress core is current.
3. Hide notices from visitors while you investigate. In wp-config.php, log warnings instead of displaying them:

   define( 'WP_DEBUG', true );
   define( 'WP_DEBUG_DISPLAY', false );
   define( 'WP_DEBUG_LOG', true );

   This keeps notices out of the page while still recording them in wp-content/debug.log.

4. Test PHP upgrades on staging. If you control the PHP version, try it on a staging copy first and review debug.log before switching production.

FAQ #

Do these notices break my site or stop old slugs from being removed? #

No. Deprecation notices are warnings. Slugs Manager keeps working; the notice only tells you that code needs updating before a future PHP version.

Which PHP version does Slugs Manager need? #

The plugin does not set a minimum PHP version of its own. Use a PHP version that your WordPress version supports, and keep Slugs Manager updated.

Should I switch back to an older PHP version? #

Usually not. Update the plugins and theme first; older PHP versions no longer receive security fixes.

Other fixes: Slugs Manager troubleshooting and “No slugs found” fix.

Warnings persist after updating? #

If a Slugs Manager notice remains after you are on the latest version, our team answers every ticket on the Slugs Manager support forum. Include your WordPress version, plugin version, PHP version, and the exact warning text so we can apply a fix if needed.