Installation MTZ-Xiaomi-related MIUI 12.5: Complete instruction with error solutions

Installing custom themes in.mtz format is one of the most popular ways to personalize the interface on Xiaomi smartphones. MIUI 12.5 offers a built-in theme store, many users prefer to install third-party solutions found on thematic forums or in telegram channels. MTZ-Files are not always intuitive, especially for beginners.

In this article, we will not only explore the standard way to import themes through Themes → My Themes, but also alternative methods for cases where the system blocks the installation. We will focus on common errors such as “Failed theme” or “File corrupted”, and explain why some themes may not work on specific Xiaomi models (for example, Redmi Note 10 Pro or Mi 11).

What is it? MTZ-Themes and Why They Are Better Than Standard

Files with the.mtz extension are archives containing all the design elements for the MIUI: Icons, wallpapers, fonts, animations and even the sounds of system notifications. MTZ-Themes are often offered:

• 🎨 Unique design that is not in the standard directory (such as iOS-style themes, Pixel Experience or retro interfaces).
• 🔧 Deep customization: changing the shape of icons, color palette of system menus, animations switching between windows.
• 📱 Adaptation to specific models (some topics are optimized for the use of the AMOLED-screens or devices with high refresh rates).
• 🚀 Regular updates from the community (as opposed to abandoned themes in the official store).

But MTZ-First, they don't pass Xiaomi's compatibility test, so they may contain bugs or conflict with system applications. Second, some themes require an unlocked bootloader or root rights to work properly. MIUI Custom theme can be reset to standard – this is the normal behavior of the system.

⚠️ Attention: Installing themes from unverified sources can lead to a leak of personal data. MTZ-Files from trusted resources like XDA Developers, Miui Themes or Official Telegram Developers Channels.

If you decide to take the risk and install a custom theme, first check its compatibility with your version. MIUI 12.5. Open the.mtz archive through any file manager (e.g., Mi File Explorer) and find the description.ini file.=12.5 or higher.

Preparing the smartphone for the installation of MTZ-theme

Before installing a theme, you need to follow several mandatory steps to avoid errors.

• 📲 The official version is installed on your device. MIUI 12.5 (Castom firmware like Xiaomi.eu or PixelExperience may have other theme installation mechanisms).
• 🔄 Developer Mode Enabled (if the theme requires additional permissions).
• 📁 The theme file (.mtz) is downloaded and located in the root folder of internal memory (for example, /storage/emulated/0/).
• 🔋 Battery charge not less than 50% (in case the installation process takes a long time).

It is also recommended to make a backup of the current theme.

1. Open Settings → Topics → My themes.
2. Find an active theme and click on the three dots in the top right corner.
3. Select Save as and specify a name for the backup.

⚠️ Note: If you use a device-based Mi Account, some custom themes may conflict with the Xiaomi Cloud cloud sync. Before installing, disable the themes sync in your account settings.

For devices with a locked bootloader (most official firmware), only installation through the standard theme menu is available. If you have a bootloader unlocked, you can use ADB or TWRP for deep customization, but this method requires experience and can lead to a device blink.

Method 1: Standard installation through "My Topics"

This is the easiest and most secure method that works on most Xiaomi devices with MIUI 12.5. Instructions are suitable for models like Redmi Note 9 Pro, Mi 10T, POCO X3 Pro and others.

Steps for installation:

1. Download a theme file with the.mtz extension and place it in any folder on internal memory (preferably the root, for example /theme.mtz).
2. Open the Themes app (the icon with a brush on your desktop).
3. Go to the My Themes tab (the person icon at the bottom of the screen).
4. Click on the + or Import icon in the upper right corner.
5. Select the downloaded.mtz file and confirm the installation.
6. After applying the theme, restart the device (this will help avoid interface glitches).

If the theme does not appear in the list after importing or if it gives an error “File corrupted”, try the following:

• 🔄 Rename the file (remove Cyrillic and spaces, for example, theme_v2.mtz).
• 📂 Put the file in the folder. MIUI/theme/ (Create it manually if you don’t).
• 🔄 Restart the device and try again.

⚠️ Note: Some devices (e.g. Mi 11 Ultra) have standard import MTZ It may be blocked due to security policy MIUI. In this case, use alternative methods from the following sections.

Method 2: Installation via ADB (for power users)

If the standard method didn’t work, you can try installing the theme via Android Debug Bridge (ADB), which requires connecting your smartphone to your computer and having basic command line knowledge.

What you need:

• 🖥️ Computer with installed ADB Fastboot (you can download from the official Android website).
• 📱 Initiated debugging mode USB on a smartphone (in Settings) → The phone. → Version. MIUI Press 7 times, then return to the Additional Settings → For developers).
• 🔌 Cable USB Type-C (preferably original).

Step-by-step:

1. Connect your smartphone to your PC and confirm the debugging permission on the device screen.
2. Open the command prompt (cmd on Windows or Terminal on macOS/Linux) and type:

adb devices

Make sure your device is listed.

1. Copy the theme file into the system folder:

adb push /path/to/file/theme.mtz /sdcard/MIUI/theme/

1. Set the theme through ADB:

adb shell am start -n com.android.themes/.module.ThemePickerActivity

After that, the smartphone screen will open a menu of choosing the ones where your custom theme should appear.

If the team fails, try an alternative method:

adb shell am broadcast -a miui.intent.action.THEME_CHANGED -p com.android.themes

⚠️ Attention: Use ADB It can lead to disruptions in work. MIUI, If the theme files conflict with system libraries, do not install themes from unknown developers.

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If the theme does not apply after installation via ADB, try clearing the theme app cache in your smartphone settings.

Method 3: Installation via TWRP (unlocked bootloader only)

This method is suitable for users who have customized TWRP recaps installed. It allows you to install themes even on informal firmware, but requires an unlocked bootloader and root rights.

Advantages of the method:

• 🔧 Possibility to install themes that are not supported in the standard way.
• 📂 Installation directly to the system partition (theme will not reset after the update) MIUI).
• 🛠️ Ability to edit theme system files manually.

Instructions:

1. Download the theme file and place it on SD-card.
2. Turn off your smartphone and press Power + Volume up to enter TWRP.
3. In the main menu, select Install (Install).
4. Find the.mtz file and swipe for confirmation.
5. After installation, restart the device.

If the theme doesn’t apply, it may be for another version of MIUI, in which case you can try:

• 🔄 Change the version in the description.ini file (opened by any text editor).
• 🔧 Install theme through Magisk (if you have root).

⚠️ Attention: Installation of those through TWRP on devices with Dynamic Partition (e.g. Xiaomi 12 or Redmi) K50) This can cause an error in the partition mounting. ADB Sideload.

Solving common errors when installing MTZ-themes

Even if you install the theme correctly, you can get crashes, and below is the table with the most common errors and ways to fix them.

If none of the methods helped, try resetting the theme settings to the standard:

1. Open Settings → Themes.
2. Select the Standard Theme (usually the first one on the list).
3. Reset the device.
4. Repeat installation MTZ-topic.

Important: Some themes require you to disable the “App Minimization” function in the special features settings, otherwise the animations will not work correctly.

Where to download safe MTZ-topic MIUI 12.5

Not all sources are equally reliable. Below are proven sites where you can find quality and safe sources. MTZ-file:

• 🌐 Official resources: XDA Developers (a section of Xiaomi Themes) – here they publish open source themes. Miui Themes (miuithemes.com) – a directory with a pre-moderator.
• 📌 Telegram channels: @miuithemes — Largest community with daily updates. @xiaomithemes — themes for Redmi and POCO.
• 🛠️ GitHub: Some developers put themes in a repository (search on request) MIUI 12.5 MTZ theme).

When downloading, pay attention to:

• 📅 Publishing Date – Old Topics (2020 and earlier) may not support MIUI 12.5.
• ⭐ Rating and reviews – if a topic has a lot of negative comments, it’s better to look for an alternative.
• 📄 Description – there should be a list of supported devices and version MIUI.

Avoid websites that:

• 🚫 Ask to disable antivirus for download.
• 💰 Requires payment for “premium themes” (most quality themes are free).
• 🔗 Redirected to suspicious domains (for example, with short links like bit.ly).

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Before installing any theme, check its hash amount (MD5/SHA-1) through services like VirusTotal to help avoid viruses and spyware.

FAQ: Frequent questions about installation MTZ-then