How to Fix WordPress Core Update Failure – Re-upload WordPress Core Files Manually (Complete Guide)

Next Level Design Agency brings you an easy-to-follow, complete guide to fix WordPress core update failures. Whether your WordPress site failed to update, got stuck in maintenance mode, or broke after an update, this article will walk you through everything you need to know — step-by-step, in plain English.

🚨 Why Do WordPress Core Updates Fail?

WordPress core updates are vital for keeping your site secure and optimized. However, many website owners face update errors like:

• “Update failed: Could not copy file.”
• “Briefly unavailable for scheduled maintenance.”
• “White Screen of Death” after updating.
• Missing files or broken site layout.

These issues usually occur because of corrupted files, plugin conflicts, or permission errors on your server. But don’t worry — re-uploading WordPress core files manually can fix everything safely.

🧩 Step 1: Backup Your WordPress Website

Before doing any manual fixes, create a full backup of your site. You can use free plugins like:

• UpdraftPlus
• All-in-One WP Migration
• Duplicator

If you prefer doing it manually, go to your hosting panel → open File Manager → download the public_html folder and export your database via phpMyAdmin.

🧰 Step 2: Download the Latest WordPress Version

Head over to the official WordPress.org download page and grab the latest version. After downloading, extract the ZIP file on your computer. You’ll get a folder named “wordpress” containing all the core files.

💻 Step 3: Connect to Your Website via FTP or File Manager

Now you’ll need to access your website files. You can use:

• FTP Client: FileZilla, CyberDuck, or WinSCP.
• cPanel File Manager: Go to public_html or your site’s root directory.

Inside that folder, you’ll find files like wp-config.php, wp-login.php, and directories like wp-admin, wp-includes, and wp-content.

🔧 Step 4: Re-upload WordPress Core Files Manually

This is the main step to fix the WordPress core update failure. Follow it carefully:

1. From the extracted WordPress folder on your computer, delete the wp-content folder. This prevents overwriting your themes and plugins.
2. Do not upload the wp-config.php file (you already have one on your server).
3. Upload all remaining files and folders to your site’s root directory.
4. When prompted, choose “Replace existing files.”

By doing this, you are replacing only the corrupted or missing core files without touching your custom content, uploads, or settings.

🧼 Step 5: Clear Cache and CDN

After the upload, clear all caches to make sure your browser and CDN aren’t showing old versions of your site. This includes:

• Browser Cache (press Ctrl + F5)
• Caching Plugin Cache (like W3 Total Cache or WP Rocket)
• CDN Cache (like Cloudflare)

If your site still shows the “maintenance mode” message, delete the .maintenance file in your root directory.

🧠 Step 6: Check File Permissions

Incorrect file permissions can cause future update failures. Make sure your permissions are correct:

• Folders: 755
• Files: 644

In your hosting File Manager, right-click any file or folder → Permissions → and adjust if necessary.

💡 Step 7: Deactivate Plugins (If Problem Persists)

Sometimes, a plugin can interfere with updates. To test this:

1. Rename the /wp-content/plugins folder to /plugins_old.
2. Try logging into your WordPress dashboard again.
3. If it works, one of your plugins was causing the issue. Rename it back to /plugins and activate each plugin one by one to identify the culprit.

🔍 Step 8: Run WordPress Site Health Check

Go to Dashboard → Tools → Site Health. This feature detects configuration errors, outdated PHP versions, and security recommendations. Follow the suggested fixes to keep your site stable and fast.

⚙️ Step 9: Enable Debug Mode (Optional)

If you still face update errors, turn on WordPress debugging to identify the problem. In your wp-config.php file, add this line:

define( 'WP_DEBUG', true );

After identifying and fixing the issue, turn it off by setting it back to false.

🔄 Step 10: Verify Your Site After Repair

After completing all steps, visit your site’s front and backend to confirm everything works correctly. Check your plugins, themes, and posts to ensure nothing broke during the repair process.

✨ Bonus Tips to Avoid Future Update Failures

• Always update plugins and themes before the core update.
• Use a staging site to test updates first.
• Choose reliable hosting with automatic backups.
• Keep PHP and MySQL versions up to date.
• Monitor site uptime using free tools like UptimeRobot.

🌟 Final Thoughts

Fixing a WordPress core update failure isn’t as scary as it sounds. By manually re-uploading the core files, clearing cache, and ensuring proper file permissions, you can restore your website without losing any content or SEO progress.

If you’re still facing technical issues or want a professional to handle WordPress maintenance, you can always reach out to Next Level Design Agency — your trusted partner for web design, development, and performance optimization.

📞 Need Expert Help?

Visit Next Level Design Agency today to get expert assistance with WordPress maintenance, performance optimization, and website recovery — handled by professionals who care about your business success.

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