How To Fix 404 Error on wp-admin – Re-upload Core Files (Complete Guide)

Have you ever tried to log in to your WordPress admin dashboard and suddenly faced a 404 error on wp-admin? This is one of the most frustrating issues for website owners, as it locks you out of the backend of your site. The good news is that this error can usually be fixed quickly by re-uploading the core WordPress files. In this article, I’ll walk you through a complete, step-by-step guide on how to fix the 404 error on wp-admin and restore access to your dashboard.

What Causes the 404 Error on wp-admin?

Before we jump into solutions, it’s important to understand why this issue happens. Some of the common causes include:

• Corrupted WordPress core files – due to incomplete updates or malware infections.
• Broken .htaccess file – incorrect rewrite rules can lead to 404 errors.
• Plugin or theme conflicts – some poorly coded plugins interfere with the admin area.
• File permission issues – incorrect server settings may block access.
• Hosting errors – sometimes server misconfigurations cause admin URLs to break.

Why Re-uploading Core Files Works

When your WordPress installation gets corrupted, the wp-admin folder or critical system files may be missing or damaged. By re-uploading the original core files from the official WordPress package, you are essentially restoring the system files without affecting your themes, plugins, or content. This method is safe and highly effective for fixing admin errors.

Step-by-Step Guide to Fix 404 Error on wp-admin

Step 1: Backup Your Website

Before making any changes, always take a full backup of your WordPress website. You can use plugins like UpdraftPlus, All-in-One WP Migration, or simply download the public_html folder and your database from cPanel.

Step 2: Download the Latest WordPress Package

Go to the official WordPress download page and get the latest version. This will ensure you’re re-uploading fresh, clean files.

Step 3: Extract the Files

Unzip the WordPress package on your computer. Inside the folder, you will find the following directories and files:

• wp-admin
• wp-includes
• wp-content
• Several PHP files like index.php, wp-config-sample.php, etc.

Step 4: Connect to Your Server

Use an FTP client (such as FileZilla) or your hosting cPanel File Manager to connect to your website’s root directory (public_html).

Step 5: Replace wp-admin and wp-includes Folders

Delete the wp-admin and wp-includes folders from your server. Then upload the fresh copies from the WordPress package. Do not delete wp-content, as this contains your themes, plugins, and uploads.

Step 6: Replace Core Files

Upload all WordPress files from the new package except the wp-content folder. Overwrite the old files when prompted. This ensures that your installation has clean system files while preserving your custom content.

Step 7: Check the .htaccess File

Sometimes, the 404 error is caused by a corrupted .htaccess file. Rename your current file to .htaccess_old and then log in to your WordPress dashboard (if accessible). Go to Settings → Permalinks and click “Save Changes” to regenerate a new .htaccess file.

Step 8: Test Your wp-admin

Now try accessing yoursite.com/wp-admin. In most cases, the 404 error will be gone, and you’ll regain full access to your admin area.

Alternative Fixes if the Problem Persists

If re-uploading the core files doesn’t work, try these additional fixes:

• Disable plugins manually – rename the plugins folder to check if a plugin is causing the issue.
• Switch to a default theme – temporarily rename your theme folder to force WordPress to use the default theme.
• Check file permissions – ensure your wp-admin and wp-includes folders have proper permissions (755 for folders, 644 for files).
• Contact your hosting provider – sometimes server configurations may need adjustments.

How to Prevent 404 Error on wp-admin in the Future

Prevention is always better than cure. Follow these tips to avoid similar issues in the future:

• Always update WordPress core, plugins, and themes regularly.
• Keep a reliable backup system in place.
• Use security plugins like Wordfence or Sucuri to protect files.
• Avoid nulled themes or plugins, as they often carry malware.
• Choose a reliable hosting provider with strong support.

Final Thoughts

Fixing the 404 error on wp-admin may seem intimidating at first, but in reality, it’s one of the easier WordPress troubleshooting tasks. By simply re-uploading the WordPress core files and ensuring your .htaccess is clean, you can restore full access to your site within minutes. Following the steps above will help you not only fix the problem but also prevent it from happening again.

If you still face issues, consider hiring a professional WordPress expert to diagnose deeper problems with your installation.

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