How To Fix Common WordPress Errors With FTP

Nothing is more stressful than a broken WordPress site and an admin dashboard that you can’t even log into. A white screen, 500 error, or “There has been a critical error on this website” message usually means a plugin, theme, or file-level problem that WordPress itself can’t fix from inside wp-admin.

The good news: you can often rescue your site by fixing these issues directly at the file system level using FTP or SEO and UX, and where you will see it in daily work.”>SFTP. With a secure FTP client, you can disable bad plugins, switch themes, repair .htaccess, increase memory limits, and even replace corrupted WordPress core files.

This tutorial walks you through step-by-step FTP fixes for the most common WordPress errors, so you can get your site back online quickly while still following solid security and backup practices (for a broader security picture, see WordPress security best practices).

Prerequisites

Before you start changing files via FTP, make sure you have a safe working environment. You’re bypassing the WordPress admin, so small mistakes can have big effects.

• Hosting account access – Logins for cPanel, Plesk, or your host’s custom dashboard to view or reset FTP/SFTP credentials.
• FTP/SFTP client installed – Such as FileZilla, Cyberduck, or WinSCP.
• Recent full backup – Files and database, so you can roll back if something goes wrong. If you don’t have one, prioritize setting up backups with a guide like Beginner Guide to WordPress Backup and Restore Strategies.
• Basic familiarity with WordPress folders – Especially wp-content, plugins, themes, and wp-config.php.

Step 1: Connect to Your WordPress Site via FTP or SFTP

Most fixes in this guide start with connecting to your server and browsing your WordPress installation. Using SFTP (encrypted) is strongly recommended over plain FTP whenever possible.

1. Find your FTP/SFTP credentials. In your hosting control panel, look for a section like “FTP Accounts”, “SFTP Access”, or “File Access”. Note the:
   • Host (often your domain or server name)
   • Port (21 for FTP, 22 for SFTP/SSH – your host will specify)
   • Username and password
2. Open your FTP client. Enter your host, username, password, and port. Choose SFTP if listed.
3. Connect and locate your WordPress folder. After connecting, on the remote side look for:
   • public_html or www (common root folders), or
   • A domain-specific folder (e.g. example.com)

   Inside, you should see files and folders such as wp-admin, wp-content, wp-includes, wp-config.php.

Step 2: Disable Problem Plugins via FTP

Many “white screen” or “critical error” issues are caused by a bad plugin update or conflict. When you can’t access wp-admin, using FTP to disable plugins is the fastest way to test this.

1. In your FTP client, open wp-content > plugins.
2. Disable all plugins at once: Right-click the plugins folder and rename it to plugins-disabled.
   • Reload your site in an incognito/private browser tab.
   • If the site loads again, a plugin is almost certainly the cause.
3. Re-enable plugins one by one:
   1. Rename plugins-disabled back to plugins.
   2. Open the plugins folder and rename each plugin folder individually, for example:
      • contact-form-7 → contact-form-7-off
   3. After renaming a plugin, reload the site. When the error disappears, the last plugin you renamed is the culprit.

Step 3: Switch or Repair Themes via FTP

A broken or incomplete theme can cause layout issues, PHP errors, or white screens—especially after a theme update gone wrong. FTP lets you force WordPress to fall back to a default theme.

1. In your FTP client, go to wp-content > themes.
2. Identify your active theme folder (it usually matches the theme’s directory name in Appearance > Themes).
3. Rename the active theme folder, for example:
   • my-business-theme → my-business-theme-broken
4. If a default theme exists (like twentytwentyfour), WordPress will try to activate it automatically once the active theme folder is missing.
5. Reload the site:
   • If it loads with the default theme, the problem is with your original theme.
   • You can then reinstall or update that theme, or debug it further.

Step 4: Repair .htaccess and Permalink-Related Errors

If your homepage loads but posts return 404s, or you see generic “500 Internal Server Error” messages, a corrupted .htaccess file is often to blame. FTP is the safest way to fix it.

1. Connect via FTP and navigate to your site root (where wp-config.php lives).
2. Download a copy of .htaccess to your computer for backup.
3. Delete the existing .htaccess file on the server.
4. Try loading your WordPress site:
   • If it loads normally, the old .htaccess was corrupt.
5. Once you can access wp-admin again, go to Settings > Permalinks and click Save Changes to regenerate .htaccess automatically.

If you can’t access wp-admin yet, you can create a fresh .htaccess manually:

1. On your computer, create a new text file named .htaccess.
2. Paste the default WordPress rules into it:

# BEGIN WordPress <IfModule mod_rewrite.c> RewriteEngine On RewriteBase / RewriteRule ^index\.php$ - [L] RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule . /index.php [L] </IfModule> # END WordPress 

3. Upload this new .htaccess file to your WordPress root via FTP.

Step 5: Increase PHP Memory Limit with wp-config.php

“Allowed memory size of X bytes exhausted” errors usually mean PHP ran out of memory. You can raise the limit for WordPress by editing wp-config.php via FTP.

1. In your site root, locate wp-config.php.
2. Download wp-config.php to your computer and open it in a code editor (not Word or a rich text editor).
3. Find the line that says:

   /* That's all, stop editing! Happy blogging. */

4. Directly above that line, add:

   define( 'WP_MEMORY_LIMIT', '256M' );

5. Save the file and upload it back to the server, overwriting the existing wp-config.php.
6. Reload your site to see if the memory error is resolved.

Step 6: Replace Corrupted WordPress Core Files via FTP

Sometimes, incomplete updates or malware infections corrupt core WordPress files. Symptoms include strange admin behavior, missing files, or repeated update failures. Replacing core files via FTP is often cleaner than trying to patch them one by one.

1. Download a clean copy of WordPress from WordPress.org that matches your current major version if possible.
2. Unzip the download on your computer. You’ll see folders like wp-admin, wp-includes, and files like index.php, wp-settings.php.
3. In your FTP client, connect to your site root.
4. Upload and overwrite the following from the fresh WordPress package:
   • Entire wp-admin folder
   • Entire wp-includes folder
   • Root WordPress files (index.php, wp-settings.php, etc.), but do not overwrite:
     • wp-config.php
     • Anything inside wp-content
5. After uploads complete, reload your site and log into wp-admin.

Restore Your WordPress Site Confidently with FTP

Using FTP (or preferably SFTP) turns a scary “site down” moment into a manageable troubleshooting task. By renaming plugin and theme folders, repairing .htaccess, increasing memory limits, and replacing core files, you can resolve many common WordPress errors even when wp-admin is completely inaccessible.

As you get comfortable with these techniques, combine them with a solid backup routine and regular maintenance so you’re not scrambling during the next outage. With safe FTP workflows and a little practice, you’ll spend less time firefighting and more time growing your WordPress site.

Further Reading

• Fixing WordPress Memory Exhausted Errors
• How to Fix JavaScript Errors in WordPress
• How to Edit WordPress Files Safely
• Common WordPress Backup Errors and How to Fix Them

Frequently Asked Questions