How to fix Delta iOS Chinese error 40021 & 40000

Delta Executor remains one of the most popular Roblox script executors for iOS users, thanks to its simple interface, reliable performance, and multiple installation options. The introduction of the direct installation method made it much easier for iPhone and iPad users to install the app without using a computer. However, many users have recently started encountering the Chinese Error 40021 and Error 40000 while trying to install Delta Executor.

These errors prevent the installation from completing and often leave users confused because the warning message is displayed entirely in Chinese. Fortunately, the issue is usually related to installation limits, expired certificates, or outdated installation files rather than a problem with your device.

This guide explains what the Chinese Error 40021 and 40000 mean, why they appear, and the most effective methods to resolve them on iPhone and iPad.

What Is Delta Executor Chinese Error 40021 and 40000?

Chinese Error 40021 and Error 40000 are installation errors that appear when users attempt to install Delta Executor through the direct installation method on iOS devices.

The notification is displayed in Chinese and generally informs users that the monthly installation quota has been exceeded. In simple terms, the certificate or installation service being used has reached its maximum number of allowed device activations.

When this limit is reached, no additional devices can install the application until the certificate is renewed or replaced.

Although the message appears in Chinese, it does not indicate that your iPhone or iPad has a hardware problem. Instead, it is related to the distribution system used for the installation.

Why Does Chinese Error 40021 or 40000 Appear?

Several different issues can trigger these errors during installation. Understanding the cause makes it much easier to choose the correct solution.

1. Monthly Installation Limit Has Been Reached

The most common reason is that the installation certificate has already been used on too many devices.

Apple limits how enterprise certificates are distributed. Once the maximum number of installations has been reached, every new installation attempt displays Error 40021 or Error 40000 until a new certificate becomes available.

This is the primary reason most users encounter the Chinese error.

2. Expired or Revoked Certificate

Delta Executor relies on enterprise certificates to install without using the App Store.

If Apple revokes or expires the certificate, iOS blocks the installation automatically. In many cases, this also triggers the Chinese error message.

Certificate revocations happen regularly, especially for third-party applications.

3. Outdated Installation File

Installing an older IPA file can also result in installation failures.

If the developer has released a newer version while the previous build is no longer supported, using an outdated installer may generate installation errors or prevent the app from launching correctly.

4. Corrupted Installation

A download that was interrupted or completed incorrectly can leave you with an incomplete IPA file.

When this happens, the installer cannot verify the application properly, causing installation failures.

5. Incorrect Direct Installation Package

Sometimes users download Delta Executor from unofficial websites that provide modified or outdated installation packages.

These files may contain incorrect identifiers or invalid certificates that iOS rejects immediately.

6. Enterprise Trust Settings Are Missing

Even after a successful installation, iOS requires users to manually trust the enterprise developer profile.

If this permission is not granted, the application may refuse to open or complete installation.

How to Fix Delta Executor Chinese Error 40021 & 40000

Follow these methods one by one until the issue is resolved.

Method 1: Remove the Existing Delta Executor

The first step is removing every existing Delta installation from your device.

• Delete Delta Executor completely.
• Remove any old installation profiles if necessary.
• Restart your iPhone or iPad.

Starting with a clean installation eliminates many common problems.

Method 2: Download the Latest Delta Executor IPA

Always use the newest available IPA file.

Older versions often stop working after certificate updates, making installation impossible.

Avoid using cached downloads or previously saved IPA files.

Method 3: Use a Sideloading Application

If direct installation keeps producing Error 40021 or Error 40000, sideloading is usually the most reliable alternative.

Popular sideloading applications can install the latest IPA manually, bypassing many of the issues caused by direct installation limits.

After installing your preferred sideloading app:

• Import the Delta Executor IPA.
• Begin the signing process.
• Install the application.
• Wait until installation finishes completely.

Many users successfully install Delta this way even when direct installation fails.

Method 4: Trust the Enterprise Developer

After installation, iOS requires manual verification.

Open your device settings and navigate to:

• Settings
• General
• VPN & Device Management

Locate the enterprise profile associated with the installation and choose Trust.

Without completing this step, Delta Executor will not launch.

Method 5: Update the Signing Certificate

Some sideloading applications rely on certificates that eventually expire.

If your signing certificate is no longer valid:

• Update the certificate.
• Import the IPA again.
• Reinstall the application.

A fresh certificate often resolves installation problems immediately.

Method 6: Try Again Later

If the monthly installation limit has genuinely been reached, there may be nothing wrong with your device.

In this situation:

• Wait until the developers replace the certificate.
• Check for updates.
• Attempt installation again later.

Many installation issues disappear once a new certificate becomes available.

Method 7: Use a VPN

Although not always necessary, switching to another network or enabling a VPN can sometimes improve connectivity during installation.

If your current connection has routing or regional issues, a VPN may help complete the download successfully.

Step-by-Step Installation Guide Using an IPA File

If direct installation is unavailable, follow these steps.

1. Delete every previous Delta Executor installation.
2. Restart your iPhone or iPad.
3. Download the latest Delta Executor IPA.
4. Install a trusted sideloading application.
5. Open the sideloading app.
6. Import the downloaded IPA.
7. Sign the application.
8. Begin installation.
9. Wait until installation completes.
10. Open Settings.
11. Navigate to VPN & Device Management.
12. Trust the enterprise profile.
13. Launch Delta Executor.

If every step is completed correctly, Delta Executor should install without displaying the Chinese error.

Quick Troubleshooting Checklist

Before attempting another installation, verify the following.

• Delete all previous Delta Executor files.
• Restart your device.
• Download only the newest IPA version.
• Avoid outdated installation links.
• Use a reliable sideloading application.
• Update expired signing certificates.
• Trust the enterprise developer profile.
• Ensure your internet connection is stable.
• Try using a VPN if necessary.
• Wait for a new certificate if installation limits have been reached.

Tips to Avoid Future Installation Errors

Although certificate-related issues cannot always be prevented, you can reduce the chances of encountering them again.

• Always install the newest release.
• Avoid unofficial or modified IPA files.
• Remove outdated versions before updating.
• Keep your sideloading application updated.
• Install only from trusted sources.
• Check for certificate updates before reinstalling.
• Keep your iOS version updated for better compatibility.

Following these practices helps minimise installation problems and ensures a smoother update experience.

Is Chinese Error 40021 Dangerous?

No.

The error itself is not harmful to your iPhone or iPad.

It simply indicates that the installation service cannot complete the installation due to certificate restrictions or installation limits.

However, downloading installation files from unverified sources can expose your device to unnecessary security risks. Always verify the authenticity of any IPA file before installing it.

Conclusion

Chinese Error 40021 and Error 40000 are among the most common installation problems faced by Delta Executor users on iPhone and iPad. In most cases, these errors occur because the enterprise certificate has exceeded Apple’s installation limit, expired, or been revoked. Fortunately, the issue is usually temporary and can often be resolved by deleting old files, downloading the latest IPA version, using a trusted sideloading application, updating the signing certificate, or waiting for a new certificate to become available.

While the direct installation method is convenient, sideloading remains one of the most dependable alternatives whenever certificate-related issues arise. Regardless of which installation method you choose, always download files from trusted sources and verify that you are installing the latest version. Following the troubleshooting methods outlined above will significantly improve your chances of installing Delta Executor successfully while reducing future installation errors.

Frequently Asked Questions