How to Fix WordPress Plugin Update Failed

by

What Is a WordPress Plugin Update Failed Error?

WordPress plugin update failures occur when you try to update a plugin and the process gets interrupted or fails to complete. You’ll see error messages like:

  • “The update failed: Could not create directory”
  • “The update failed: download failed”
  • “A plugin file failed to verify its authenticity”
  • “Connection timed out during update”
  • “Unable to move file”
  • “The remote response was not in the correct format”

After encountering this error, the plugin often remains partially updated—neither the old version nor the new version works properly. This can leave your site in a broken state where the plugin is disabled or functions unpredictably.

Unlike update failures that result in a 500 error, plugin update failures are specific to the update mechanism itself. Your site might still load, but that particular plugin stops working.

Common Causes of Plugin Update Failures

  • Insufficient file permissions — WordPress can’t write updated files
  • Disk space full — Server storage at capacity, update can’t write new files
  • Memory limit too low — Plugin update process requires more PHP memory
  • Connection timeout — Download from WordPress.org takes too long
  • Plugin file is corrupted — Current plugin has issues preventing updates
  • Security plugin blocking update — Firewall rules preventing file modifications
  • FTP/SFTP credentials missing — WordPress needs these to update files
  • Server execution time limit — Update process times out before completing
  • Plugin authentication verification failed — WordPress can’t verify plugin from wordpress.org
  • Incomplete previous update — Leftover files from earlier failed update

Solution 1: Check File Permissions

This is the #1 cause of update failures. WordPress needs write access to the plugins directory.

Correct permissions:

  • /wp-content/plugins/ directory: 755
  • Plugin files inside: 644

Via FTP:

  1. Connect via FTP
  2. Navigate to /wp-content/plugins/
  3. Right-click the folder
  4. Select “File Permissions” or “Change Permissions”
  5. Set to 755
  6. Check “Apply to directories only”
  7. Click OK

Via SSH:

cd /home/username/public_html/wp-content/plugins
chmod 755 .
find . -type f -exec chmod 644 {} \;

After fixing permissions, try updating the plugin again via Plugins → Installed Plugins.

Solution 2: Increase PHP Memory and Execution Limits

Plugin updates are resource-intensive. Insufficient limits cause failures mid-process.

Edit wp-config.php:

Add before /* That's all, stop editing! */:

define('WP_MEMORY_LIMIT', '256M');
define('WP_MAX_MEMORY_LIMIT', '512M');
set_time_limit(600);

Or edit php.ini:

memory_limit = 256M
max_execution_time = 600
max_input_time = 600
upload_max_filesize = 128M

Or edit .htaccess:

php_value memory_limit 256M
php_value max_execution_time 600
php_value upload_max_filesize 128M

Save and try updating again.

Solution 3: Check Available Disk Space

If the server has no free space, update processes fail when trying to write new files.

Check disk usage:

Via cPanel:

  1. Log in to cPanel
  2. Check the disk usage meter (top right)
  3. If near 100%, you’re running out of space

Via SSH:

df -h

Free up space by deleting:

  1. Old backup files (/home/username/backups/)
  2. Unused themes in /wp-content/themes/
  3. Old plugin installations you replaced
  4. Temporary cache files
  5. Old WordPress install copies

Once you have at least 20% free space, try updating the plugin again.

Solution 4: Manually Update via FTP

If the update keeps failing through WordPress admin, update manually via FTP.

Step 1: Download the new plugin version

  1. Go to wordpress.org/plugins/[plugin-name]
  2. Click “Download” to get the latest ZIP file

Step 2: Extract and upload

  1. Extract the ZIP file on your computer
  2. Via FTP, navigate to /wp-content/plugins/
  3. Delete the entire folder for the plugin you’re updating
  4. Upload the extracted plugin folder
  5. Go to WordPress admin → Plugins → Installed Plugins
  6. Activate the plugin

Solution 5: Disable Background Updates and Try Manual Update

WordPress’s background update process might be interfering.

  1. Add to wp-config.php:
define('AUTOMATIC_UPDATER_DISABLED', true);
  1. Now manually update the plugin via Plugins → Installed Plugins → Update Available
  2. After successful update, you can remove or keep this setting

This forces WordPress to use the interactive update process instead of background updates.

Solution 6: Clear Plugin Update Cache

WordPress caches plugin information. Corrupt cache can cause update failures.

Add to wp-config.php temporarily:

define('WP_DISABLE_FATAL_ERROR_HANDLER', true);

Or manually clear cache:

  1. Via phpMyAdmin, open wp_options table
  2. Find rows with option_name containing transient or update_plugins
  3. Delete those rows

Then try updating again. WordPress will regenerate fresh cache.

Solution 7: Disable Security Plugins Temporarily

Security plugins sometimes block file modifications during updates.

Via WordPress:

  1. Go to Plugins → Installed Plugins
  2. Deactivate security plugins (Wordfence, iThemes Security, Sucuri, etc.)
  3. Try updating the plugin
  4. Re-enable security plugins after successful update

Via FTP (if locked out):

  1. Rename /wp-content/plugins/wordfence to /wp-content/plugins/wordfence-disabled
  2. Try updating
  3. Rename back to enable

Solution 8: Check WordPress Core Files Are Intact

Corrupt WordPress core files can prevent plugin updates.

  1. Download WordPress from wordpress.org
  2. Extract the ZIP file
  3. Delete the wp-content folder from extracted files
  4. Via FTP, upload all remaining files to your WordPress root
  5. Choose “Overwrite” when prompted
  6. Try updating the plugin again

This refreshes WordPress core files without affecting your content.

Solution 9: Remove Partially Updated Plugin Files

If a previous update left incomplete files, clean them first.

  1. Via FTP, navigate to /wp-content/plugins/[plugin-name]/
  2. Look for files with .tmp, .backup, or .old extensions
  3. Delete all temporary files
  4. Also check if there are duplicate plugin folders (like plugin-name-2 or plugin-name.old)
  5. Delete any duplicates
  6. Try updating again

Sometimes leftover files from failed updates prevent new updates.

Solution 10: Check SFTP/FTP Credentials

WordPress might need file transfer credentials to update plugins.

  1. Go to WordPress admin
  2. Go to Plugins → Installed Plugins
  3. Click “Update” on a plugin
  4. If prompted for FTP/SFTP credentials, enter them correctly
  5. Get credentials from your hosting control panel if needed

To automate this, add to wp-config.php:

define('FTP_HOST', 'ftp.yourdomain.com');
define('FTP_USER', 'ftp_username');
define('FTP_PASS', 'ftp_password');
define('FTP_SSL', false);

This prevents WordPress from asking for credentials on every update.

Solution 11: Temporarily Increase Server Resources via Hosting Panel

If memory and execution limits don’t help, ask your host to increase server resources.

  1. Log in to hosting control panel (cPanel, Plesk)
  2. Find “Resource Limits” or “PHP Configuration”
  3. Request temporary increase to:
    • Memory: 1GB for the update
    • Execution time: 15 minutes
  4. Update the plugin
  5. Reset to normal values

Most quality hosts can do this via the control panel without contacting support.

Solution 12: Enable Debug Logging

See exactly why the update is failing.

Add to wp-config.php:

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

Try updating the plugin, then check /wp-content/debug.log for detailed error messages showing the exact failure point.

Solution 13: Check for Conflicting Updates

Sometimes updating one plugin breaks another. Test updates individually.

  1. Update one plugin at a time
  2. Wait 10 minutes between updates
  3. Test your site after each update
  4. If one update breaks something, revert it and contact the plugin developer

Never bulk-update 10 plugins simultaneously—you can’t identify which one caused problems.

Solution 14: Reinstall the Plugin Cleanly

If nothing else works, remove and reinstall the plugin fresh.

  1. Go to Plugins → Installed Plugins
  2. Deactivate the problem plugin
  3. Click “Delete”
  4. Go to Plugins → Add New
  5. Search for the plugin
  6. Click “Install Now”
  7. Activate it

This gives you the latest version without the update process that was failing.

Prevention Tips

  • Set correct file permissions (755 on directories, 644 on files) from the start
  • Keep at least 20% disk space free at all times
  • Disable automatic updates while testing new plugins
  • Update plugins individually, one at a time
  • Monitor updates in a changelog before applying
  • Keep WordPress core, PHP, and plugins updated regularly
  • Test plugin updates on staging sites first
  • Monitor disk space and server resources regularly
  • Enable debug logging during updates for troubleshooting

From experience: A client had chronic plugin update failures until I discovered they had a security plugin that required manual approval for every file modification. Whitelisting the plugin update process in their security settings fixed the issue permanently. Sometimes the cause isn’t technical—it’s overly restrictive security settings blocking legitimate operations.

Related: Plugin update failures sometimes overlap with other WordPress errors. Check How to Fix WordPress Server Error After Update or How to Fix Wordfence Blocking Admin Access if updates cause additional problems.

Conclusion

WordPress plugin update failures are usually caused by insufficient file permissions, low memory limits, or full disk space. Check permissions and increase memory first—these solve 80% of cases. If those don’t work, manually update via FTP as a reliable fallback. The key is understanding that updates are resource-intensive operations that need proper server configuration and available disk space. Setting these up correctly from the start prevents most update issues entirely.

Leave a Comment