Install a downloaded theme on Xiaomi MIUI 12: Complete instructions with nuances

Updating the appearance of the smartphone through custom themes is one of the key features of the shell MIUI 12.But many users have trouble installing downloaded.mtz files from the Internet. The official theme store offers limited choice, and third-party resources require a special approach to installation. In this article, we will discuss all the working ways to integrate themes into the system, including bypassing typical errors such as “File corrupted” or “Unsupported format".

It's important to understand: MIUI 12 has strict restrictions on installing unsigned themes due to Xiaomi's security policy. MIUI 13/14 The algorithms have been tightened, but there are still working loopholes for version twelve, and we're going to look at both legal methods through built-in tools and alternative solutions for advanced users. 9 Pro, Mi 10T and POCO X3 NFC global and Chinese firmware.

Preparation: where to download topics and what format is needed

Before you start installing, make sure you have the correct theme file.Themes official store in the MIUI It offers a limited catalog, so most users search for themes on third-party sites:

• 🌐 Zedge is the largest database of filtered themes for screen resolution. HD+ Xiaomi displays.
• 🎨 MIUI Themes (miuithemes.com) – a specialized site with themes optimized for the user. MIUI 12.
• 📱 Telegram channels like @MIUI_Themes or @XiaomiThemes, where exclusive assemblies are placed.
• 🔍 4PDA — Russian-language forum with a section of custom topics for specific models Xiaomi/Redmi/POCO.

Pay attention to the file format: the theme should be in the.mtz extension (MIUI Theme Zip..apk or.zip files will not work without conversion. MIUI, The theme is intended for – some builds work only on the MIUI 12.0.x or 12.5.x. Information is usually specified in the description of the file.

⚠️ Note: Only download themes from trusted sources..mtz files may contain malicious code that will access system permissions. Before installing, check the file through VirusTotal.

*To install themes with animations on MIUI 12 may require unlocking the bootloader and root rights. Without them, the system will block the use of some elements.

Method 1: Installation through the standard themes menu (without root)

The easiest and safest method is to use the built-in Themes app, which is suitable for most.mtz files, but has limitations in the size and structure of the theme.

Steps for installation:

1. Download the theme file (.mtz) to your device, and we recommend saving it to the Download folder or MIUI/theme (Create it manually).
2. Open the Themes app (brush icon on desktop).
3. Go to the section My topics → Import (in upper right corner).
4. Select the downloaded.mtz file and confirm the installation.
5. After importing the theme will appear in the list My themes. Click on it and select Apply.

If the theme does not appear in the list after import, check:

• 📌 File extension (should be.mtz, not.mtz.mtz.zip).
• 📌 File integrity – try to download it again.
• 📌 Free space in the memory of the device (requires a minimum of 200 MB).

⚠️ Attention: On some firmware MIUI 12 for the Chinese region (China) ROM) Theme import function is disabled via Themes menu. Use Method 2.

Download.mtz file from a verified source|

Check the integrity of the file (size, hash amount)|

Create a folder. MIUI/theme inner-memory|

Free up at least 200 MB of memory|

Shut down. VPN (It can block access to servers. MIUI)-->

Method 2: Installation through file manager (alternative method)

If standard import doesn’t work, try installing the theme through a file manager, which bypasses some system limitations but requires you to follow the instructions exactly.

Instructions:

1. Download and install a file manager with support for system folders, such as MiXplorer or Solid Explorer.
2. Move the.mtz file to the folder: /storage/emulated/0/MIUI/theme/ (if MIUI Or theme not – create them manually).
3. Reset the device (required!).
4. Open Themes. → My topics, your topic should be on the list.

If the theme doesn’t show up, try the following:

• 🔄 Rename the theme file to Latin without spaces (e.g, dark_theme_v2.mtz).
• 📂 Check the access rights to the folder MIUI/theme — they should be 755 (Use the rights to view FX File Explorer with Root Mode enabled).
• 🔄 Restart the device in Safe Mode (hold the switch off button). → "Restart in Safe Mode, then try again.

Critical detail: on firmware MIUI 12.5 and later, the system can block themes with modified system icons, in which case only part of the elements (wallpaper, fonts) will be used, and the icons will remain standard.

💡

If after installing the theme, app icons disappear, reset the Themes app cache in the settings: Settings → Annexes → Application management → Topics → Warehouse → Clear the cache.

Method 3: Installation via ADB (for power users)

If the first two methods didn’t work, you can try installing the theme through Android Debug Bridge (ADB). This method requires a PC connection and basic command line knowledge, but gives more control over the process.

Step-by-step:

1. Enable USB Debugging on your smartphone: Settings → About Phone → MIUI Version (click 7 times) Settings → Additional → For Developers → Debugging on USB
2. Connect the device to the PC and confirm the debugging permission.
3. Download ADB Tools and unpack into any folder on your PC.
4. Place the.mtz file in the platform-tools folder and rename it to theme.mtz.
5. Open the command line in the platform-tools folder and execute the commands: adb push theme.mtz /sdcard/MIUI/theme/ adb shell am broadcast -a miui.intent.action.CHANGE_THEME --ez success true
6. Reboot the device. The theme should appear in the list of My Topics.

If the adb push command produces a Read-only file system error, do:

adb shell


su




mount -o rw,remount /system




exit




exit

Then repeat the adb push command.

⚠️ Attention: Use ADB root can cause a system failure if you run wrong commands!

Solving common errors when installing themes

Even if you follow instructions correctly, users often encounter errors, and let's look at the typical problems and how to fix them.

The error "The subject contains inadmissible elements" is particularly noteworthy, and it occurs when the.mtz file contains:

• 📛 Modified system icons (e.g. Settings, Phone, Messages).
• 🎭 Animations to lock the screen or menu.
• 🔊 Castomic notification sounds (in) MIUI 12 their installation is blocked).

In this case, only manual editing of the.mtz file (deletion of prohibited elements) or installation through Magisk with a module will help. MIUI Theme Engine Enabler.

💡

If the theme is partially applied (for example, only the wallpaper changes), the problem is the restrictions. MIUI. Full customization is possible only with root rights or through alternative launchers.

How to Remove or Reset an Established Theme

If a new theme doesn't work properly or you don't like the result, you can delete it or reset it to a standard one.

Method 1: Through the Topic Menu

1. Open Themes. → My subjects.
2. Find the set theme and click on it.
3. Select Remove (Basket icon).
4. Confirm the deletion and apply the standard theme (Default).

Method 2: Resetting through settings

1. Go to Settings → Themes.
2. Choose Standard or Default.
3. Confirm application.

Method 3: Cleaning the cache (if the topic is “hangy”)

1. Open Settings → Applications → Application Management.
2. Find Themes and select Warehouse.
3. Click Clear cache and Clear data.
4. Reset the device.

If you have artifacts left after removing the theme (for example, old wallpaper or fonts), perform a complete style reset:

Settings → Additional → Resetting settings → Resetting the design style

Additional advice on working with topics on MIUI 12

To avoid problems with topics in the future, follow these guidelines:

• 🔄 Update your firmware regularly. MIUI 12 corrected bugs with the display of themes.
• 📁 Backup your favorite themes by copying.mtz files to the cloud or PC.
• 🛠️ Use alternative launchers (like Nova Launcher or Hyperion) to flexibly customize your icons.
• 🔍 Check the themes are compatible with your screen resolution. FHD+ They may not be correctly displayed on HD+-display.

For advanced users:

• 🔧 Install the module. MIUI Theme Engine Enabler via Magisk to get around system limitations.
• 🎨 Use it. MT Manager for editing.mtz files and removing blocked items.
• 📱 Configure Always-On Display through the app AOD Customizer (root required).

If you often experiment with topics, consider creating a separate user profile in the user experience. MIUI:

Settings → System → Multiplayer Mode → Add the User

This will allow you to test topics without risk for your main profile.

💡

To speed up the application of themes, before installing a new one, turn off animations in the developer settings: Settings → For developers → The scale of window animation (off.).

FAQ: Frequent questions about setting topics on MIUI 12