The Xiaomi Mi 9, despite its age, remains a popular device due to its excellent screen and performance. However, often after upgrading to a new version of MIUI, users face bugs, reduced autonomy or simply an unusual interface.
The rollback procedure, or downgrade, requires care, as Xiaomi's security system has rollback protection. It is critical to check the Anti-Rollback version number, since running an older version on a locked bootloader can lead to a "bricking" of the device. Below we will discuss safe methods for returning to a stable build.
Before we start, we need to understand the risks, and any interference with software has potential threats.
⚠️ Note: All actions for flashing you perform at your own risk.The author is not responsible for possible loss of data or failure of the device.
Checking the possibility of rollback and anti-Rollback
The first step is to analyze the current situation: modern Xiaomi smartphones have anti-Rollback (ARB) protection, a mechanism that prohibits installing an older version of the firmware if it contains a lower security index.
To find out the current version of protection, go to the settings menu. You need to find the About Phone section and click on the MIUI version several times. An extended menu will open where you can see the ARB index. If the new firmware index is higher than the one you want to install, the standard method through Recovery will not work without unlocking the bootloader.
There are several ways to bring back the old system:
- 📱 Local update via Recovery menu (only works with the same index) ARB).
- 💻 Full Fastboot Fastboot and Mi Flash Tool.
- 🔓 Official unlocking of the bootloader (Bootloader) for installation of any version.
What is the Anti-Rollback Index?
If you are not sure of your abilities, it is better to wait for the bug fix in the new version of MIUI. However, if the problem is critical, move to the next section for tool preparation.
Preparation of the device and necessary files
To successfully perform the downgrade procedure on the Xiaomi Mi 9 (codenamed cepheus) will require careful preparation. USB-You need to create a full backup of the data first, because the rollback process involves completely erasing the information.
Download the exact firmware version you plan to upgrade to. Files should be in.zip format for Recovery method or.tgz format for Fastboot method. Official archives are best taken from trusted resources such as miui.com or specialized forums to avoid malicious code.
☑️ Checklist for preparation for downgrade
Put the downloaded firmware file in the root of the phone's internal memory if you plan to use the menu update method. Call the file simply, like update.zip, to avoid errors when reading the path. Make sure the file is not corrupted when downloading.
Method 1: Local Update with Recovery
This is the least risky method, but it only works if the firmware version you want to roll back on has the same or higher Anti-Rollback index than the current one. If the indexes don't match, the system will issue an error and disallow the installation.
To start, activate the advanced features in the update menu. Go to Settings → About Phone and tap on MIUI before you hear the update message, then open the update menu and click on the three dots in the upper right corner. Select Select the firmware file and specify the path to your update.zip archive.
After selecting the file, the phone will suggest rebooting to Recovery mode. Confirm action. From the menu that opens, select the language (usually available in English and Chinese) and click Install update.zip. The system will check the integrity of the file and version compatibility.
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If the system writes "Can't verify update" or "Current version is newer" after selecting the file, it means that direct recoil through Recovery is impossible due to the Anti-Rollback protection, in which case only the unlocked bootloader method will help.
If the test is successful, the installation process will begin. Don't interrupt it or press buttons. Once completed, the phone will automatically restart. The first run may take longer than usual, as the applications are optimized.
Method 2: Complete Downgrade via Fastboot and Mi Flash
If the standard method didn't work, a more radical approach using PC and Fastboot mode would be needed.This method allows you to completely replace the system partition, ignoring some checks, but it requires an unlocked bootloader.Without an unlocked Bootloader, installing an older global firmware is often impossible.
First, you need to put the Xiaomi Mi 9 into Fastboot mode. Turn off the phone completely, then press the power and volume buttons at the same time. When an image of a rabbit repairing an android appears, connect the device to your computer. Make sure that the Windows Device Manager defines the phone as Android Bootloader Interface.
Launch the Mi Flash Tool on behalf of the administrator. Press the Refresh button so that the program can see your device. Then select the folder with the unpacked firmware (the.tgz archive must be pre-unpacked). In the lower right corner, select Clean all mode to avoid file conflicts.
The table below will help you understand the firmware modes in the Mi Flash Tool:
| Regime. | Data retention | Risk of error | Recommendation |
|---|---|---|---|
| Update | Yes. | High-pitched | Not recommended for downgrade |
| Clean all | No. | Medium. | The best option for a rollback |
| Clean all and lock | No. | High-pitched | Only if the regions are the same |
Once you select the mode, press Flash. It takes 200 to 500 seconds. When it's finished, the phone will go into reboot. If the device has gone into a bootloop, it's possible that the firmware version is incompatible with the current bootloader.
Problems of compatibility of regions and versions
One of the common reasons for downgrade failures is regional mismatch. For example, on the Xiaomi Mi 9 with an unlocked bootloader, you can install Chinese firmware on top of the global one, but the reverse action can cause errors in the communication modules. The system may stop seeing the network or working with frequencies.
There is also the notion of cross-regional updates, and if you're trying to roll back from the Global ROM to the older Global ROM, there's usually no problem (assuming the ARB matches), but switching between branches (e.g. China -> Global) requires data cleaning and often manual flashing through the Fastboot.
⚠️ Note: When you run the Chinese version on the global device (or vice versa) without proper preparation can fly certificate Widevine L1, Streaming services (Netflix) will no longer show content in the Internet. HD quality.
Always check the device type before downloading the firmware. Xiaomi Mi 9 is codenamed cepheus.Do not try to flash files from Mi 9 SE (pyxis) or Mi 9T (davinci), this is guaranteed to break.
Frequent mistakes and ways to solve them
In the rollback process, users often face typical problems, such as a “Status 7” error when installed via Recovery means that the installation script cannot find the desired version of the Android or the protection index above the allowed one, and this is solved only by the Fastboot method.
Another common problem is hanging on the MI logo. If the phone is hanging on the screensaver for more than 10 minutes, try resetting via Recovery (Wipe Data). If that doesn't work, you'll need to reflash through Mi Flash with a Clean all mode selection.
You may also have problems with the drivers on your computer, and if the Mi Flash Tool can't see the phone,
- 🔌 Try another one. USB-cable USB (preferably USB 2.0).
- 💻 Reinstall the drivers ADB/Fastboot via device manager.
- 🔄 Restart your computer and re-enter Fastboot mode on your phone.
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The main rule of a successful downgrade is to always have an unlocked bootloader and an exact copy of the factory firmware designed specifically for your model and region.
Remember that after rolling back on an older version of Android, some new apps may stop working properly, requiring an update or finding old ones. APK-file.
Final recommendations and safety
Going back to the previous MIUI version on the Xiaomi Mi 9 is a temporary solution. Developers release updates for a reason, often closing security vulnerabilities. Using old firmware, you potentially put your data at risk.
After a successful rollback, it is recommended to immediately disable automatic system updates so that the phone does not start downloading the problematic version again, this can be done by removing the Update app or restricting its access to the network through application settings.
Keep an eye out for Xiaomi's official forums. Often users find ways to fix new firmware bugs without having to roll back, using special patches or resetting certain settings. Downgrade should be used as a last resort when other methods don't help.