Download Failed - The Checksum of the File Does Not Match the Expected Checksum Value Installation Failed

Learn how to fix the “Download failed. The checksum of the file does not match the expected checksum value. Installation failed.” error in WordPress with proven solutions.

Download Failed – The Checksum of the File Does Not Match the Expected Checksum Value Installation Failed

If you’re updating WordPress, installing a plugin, or updating a theme and receive the following error:

Download failed.: The checksum of the file does not match the expected checksum value.
Installation failed.

it means WordPress downloaded a file, but the downloaded file’s checksum doesn’t match the original checksum provided by the source. WordPress blocks the installation to protect your website from corrupted or modified files.

Fortunately, this issue is usually easy to fix. Follow the methods below one by one until the problem is resolved.

Check Disk Space and Database Usage First

Before trying any other solution, check your hosting account’s disk usage and MySQL database storage.

If your hosting account has reached its storage limit, WordPress may not be able to download or extract update files correctly. This frequently results in checksum verification errors.

Check the following:

Disk Usage
Available Storage Space
MySQL Database Size
MySQL Disk Quota (if applicable)
Inode Usage (many hosting providers limit the number of files)

If any of these resources are full or nearly full:

Delete unnecessary backups.
Remove old log files.
Delete unused themes and plugins.
Clear cache folders.
Remove unnecessary media files.
Increase your hosting storage if required.

After freeing up enough space, try the update again.

Clear the WordPress Upgrade Directory

WordPress temporarily stores update files inside the upgrade directory.

Delete everything inside:

wp-content/upgrade/

Do not delete the folder itself—only its contents.

Now retry the update.

Try the Update Again

Sometimes the downloaded ZIP file becomes corrupted because of a temporary network interruption.

Simply:

Go to Dashboard → Updates
Click Update Now again.

Many users find that the second attempt downloads a fresh copy successfully.

Clear All Website Caches

Caching services can occasionally serve an outdated or corrupted ZIP archive.

Clear every cache you use, including:

WordPress cache plugin
Object cache
Server cache
LiteSpeed Cache
NGINX FastCGI Cache
Varnish Cache
Cloudflare Cache
Browser Cache

After clearing the cache, retry the installation.

Verify Your SSL Configuration

WordPress downloads updates securely over HTTPS.

If your server has an invalid SSL certificate or outdated CA certificates, downloaded files may fail checksum verification.

Check that:

SSL certificate is valid.
OpenSSL is up to date.
cURL supports HTTPS correctly.
CA certificates are installed properly.

If you previously disabled SSL verification using custom code, remove it and restore the default WordPress behavior.

Disable Security Software Temporarily

Some firewalls or security plugins inspect downloaded files and may modify them during scanning.

Temporarily disable:

Security plugins
Web Application Firewall (WAF)
ModSecurity (if available)

After testing, remember to enable them again.

Check File Permissions

Incorrect file permissions can prevent WordPress from extracting update files properly.

Recommended permissions:

Directories

Files

Also ensure that the web server user has write permission to:

wp-content

and

wp-content/upgrade

Update WordPress Manually

If automatic updates continue to fail, perform a manual update.

Download the latest WordPress package from WordPress.org.
Extract the ZIP file.
Upload the following folders:
- wp-admin
- wp-includes
Replace all root files except:
- wp-config.php
- wp-content folder

This bypasses the automatic download process entirely.

Update Using WP-CLI

If your hosting provides SSH access, WP-CLI is often the most reliable option.

Run:

wp core update

If necessary, force a fresh download:

wp core download --force

WP-CLI downloads a clean copy directly from the official servers.

Disable CDN Temporarily

If you’re using:

Cloudflare
BunnyCDN
Sucuri CDN
QUIC.cloud

temporarily disable or bypass the CDN while performing the update.

Then try again.

Check Hosting Server Health

Sometimes the issue originates from the hosting server.

Ask your hosting provider to verify:

Disk health
Server file system
Temporary directory permissions
PHP temporary directory
cURL functionality
SSL certificates
Network connectivity to WordPress.org

Scan Your Website for Malware

If malware has modified WordPress core files or intercepted downloads, checksum verification will fail.

Run a complete malware scan and remove any infected files before attempting another update.

Reinstall the Plugin or Theme

If the checksum error only affects a specific plugin or theme:

Delete the existing copy.
Download a fresh copy from the official source.
Upload and install it again.

Avoid using modified or nulled versions.

Contact Your Hosting Provider

If none of the above solutions work, contact your hosting provider.

Provide:

Complete error message
WordPress version
PHP version
Hosting control panel
Server logs (if available)

This helps them identify server-side issues quickly.

Why Does This Error Occur?

The checksum verification process compares the downloaded file with the original file published by the developer.

If even a single byte differs, WordPress assumes the file may be corrupted, incomplete, or modified and immediately stops the installation to protect your website.

Common causes include:

Full disk storage
Full database quota
Corrupted download
Cache corruption
SSL issues
Server permission problems
CDN interference
Malware
Hosting server issues

Frequently Asked Questions

Can low disk space cause this checksum error?

Yes. If your hosting account runs out of storage, WordPress may fail to download or extract update files correctly, leading to checksum verification failures.

Can Cloudflare cause checksum mismatch errors?

Although uncommon, cached or interrupted downloads through a CDN can sometimes result in corrupted update packages.

Is it safe to disable checksum verification?

No. Checksum verification is an important security feature that protects your website from corrupted or tampered files.

Should I manually update WordPress if automatic updates fail?

Yes. Manual updates are an official and safe alternative when automatic updates repeatedly fail.

Conclusion

The “Download failed. The checksum of the file does not match the expected checksum value. Installation failed.” error is usually caused by storage limitations, corrupted downloads, caching, SSL problems, or server configuration issues.

Always begin by checking disk usage, available storage, MySQL database space, and inode usage, as these are among the most common causes. Once sufficient storage is available, continue with the remaining troubleshooting methods until the update completes successfully.