Owners of modern smartphones Xiaomi, Redmi and POCO often face the need to work with text files, spreadsheets and presentations directly on a mobile device.The situation when you download an important contract, textbook or invoice, and the phone offers to choose an application or does not respond to clicking, is familiar to many, because of the features of the shell MIUI or HyperOS, which can handle file types differently depending on the version of Android.
The problem is usually not the absence of a file, but the lack of association of the format with a particular program. The system simply does not know what it needs to run this object. In most cases, one correct action is enough to open the file. However, sometimes a deeper intervention is required in settings or installing specialized software.
In this article, we will look at all possible scenarios, from simple actions to solving complex program conflicts, you will learn how to configure the file manager by default and which formats are supported out of the box.
Standard System Tools for Viewing Files
The Android operating system on which Xiaomi phones are based has a built-in file processing mechanism. First of all, check the standard file manager, which is preinstalled on all devices of the brand, usually called “File Manager” or “File Manager” and has a characteristic yellow icon with a folder.
When you try to run a file through this tool, the system automatically scans the installed applications for support for this extension. If a suitable program is found, the document will open instantly. The built-in viewer is great at basic image formats, simple text files and PDF.
However, standard tools are often limited in functionality, which may not display complex formatting in Word documents or allow you to edit Excel tables, in which case the system will either offer a read-only mode or display a format error.
- 📁 Standard "Conductor" automatically sorts files into categories: pictures, videos, documents.
- 👁️ The built-in rendering engine allows you to quickly PDF heavy-software.
- ⚙️ The settings for displaying hidden files are located in the “Settings” menu inside the conductor itself.
It's important to understand that standard tools are just a basic level, and for full work with office suites, it's better to use specialized applications that give access to editing and cloud storage.
☑️ Checking basic settings
Popular document formats and how to open them
The world of office files is diverse, and each format requires a different approach. On Xiaomi devices, the three main groups of documents most commonly found are text editors, spreadsheets, and Portable Document Format. Understanding the differences between them will help you choose the right tool.
The DOC and DOCX formats are owned by Microsoft, and for their correct display, especially if the text has tables, footers or complex layout, the best official applications or their qualitative counterparts are best suited. Simple text viewers can “break” the structure of the page.
PDF is designed to be universal in any device without changing the layout. It's not designed to be easy to edit, but it's ideal for reading books, instructions, and contracts. For PDF, there are many lightweight readers that consume minimal battery life.
| File format | Description | Recommended annex | Editing capability |
|---|---|---|---|
| .doc,.docx | Word text document | Microsoft Word, WPS Office | Complete. |
| .xls,.xlsx | Excel spreadsheet | Microsoft Excel, Google Tables | Complete. |
| Fixed layout document | Adobe Acrobat, Google PDF Viewer | Limited. | |
| .txt | Simple text without formatting | Any text editor | Complete. |
| .ppt,.pptx | Presentation of PowerPoint | Microsoft PowerPoint, WPS Office | Complete. |
The.zip and.rar archives are also worth mentioning. Before opening a document inside them, the file must be unpacked. Xiaomi’s standard Explorer can work with zip archives, but rar may require a third-party application, such as ZArchiver.
What to do with unknown extensions?
Solving the problem of “Not selected application”
One of the most common problems with MIUI is that it pops up with the message “No App Selected” or “No Action Supported” when you try to run a file, which means that there is no program on the system that tells the operating system that it is ready to work with this type of data.
First of all, you need to make sure that the reader application is actually installed. Sometimes users delete office suites in pursuit of free space, forgetting that without them to open attachments from mail or messengers will not be able. Check the list of installed programs in the Settings → Applications → All applications.
⚠️ Attention: If you click on the selection menu file and you don't see any selections at all, but you just have a vibration or nothing happens, you may have lost the file association in the system.
The second step is to force the program to be selected. When you see an Open with Help window, don't be too quick to tick the Always box if you're not sure about the choice. You'd better choose Only Once and check how the document is displayed. If the formatting is on, then you'll want to choose another app next time.
Sometimes it helps to clean the cache of the standard file manager. Go to Settings → Applications → All applications → Explorer → Memory and click Clear cache. This will not delete your files, but will reset temporary indexing errors.
Installation and configuration of office packages
Xiaomi needs a robust office suite to work comfortably, and there are plenty of options available in the Google Play store, but not all are equally well optimized for mobile screens and Snapdragon or MediaTek processors.
One of the most popular solutions is WPS Office, which is often pre-installed on Xiaomi smartphones in some regions, opens almost all formats and has a user-friendly interface, but the free version may contain ads that pop up when you run documents.
Microsoft products are an alternative. Word, Excel and PowerPoint applications can be combined into one app, Microsoft 365 (Office), which guarantees perfect compatibility, but requires a Microsoft account to fully edit on screens larger than 10 inches (on phones editing is usually free).
- 📝 Google Docs – Great for Collaboration and Auto-Save in the Cloud.
- 📚 ReadEra is the best choice for reading books and PDF functionless.
- 📊 OfficeSuite is a powerful combine with support for many formats, including PDF-editor.
When installing a new application, the system may ask if it should be used by default for certain file types, and this is a good time to assign a priority program so that the selection window does not appear in the future.
💡
Use lightweight versions of apps (Lite) if your smartphone has less than 4GB of RAM. They take up less space and open heavy documents faster.
Setup of Third Party File Managers
Xiaomi’s standard Explorer is functional, but sometimes users prefer more advanced tools like Solid Explorer, FX File Explorer or Files by Google.These apps provide more flexible display and file management settings.
The main advantage of third-party managers is the ability to fine-tune MIME-You can manually specify that files with the.epub extension should always open in a particular reader, ignoring system preferences.
In addition, advanced managers allow you to connect cloud storage (Google Drive, Dropbox, OneDrive) as network drives, which allows you to open documents that do not physically take up space on the phone, downloading them as needed.
To work with system files or hidden folders, you may need access to the root directory. Be careful: changing system files through the file manager can lead to unstable HyperOS operation.
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A third-party file manager gives more control over file associations than a standard MIUI explorer.
Frequent errors and ways to fix them
Even with all the applications, there can be specific errors, such as opening a document, but instead of text, you can see "krakozyak" or empty squares, which indicates a problem with encoding or lack of necessary fonts in the system.
If a file is corrupted when downloading (for example, a connection is cut off), no application can open it, and in such cases, often a message is issued saying "File is not supported" or "Syntax analysis error", the solution is one - to download the file again, preferably through a stable Wi-Fi connection.
⚠️ Warning: Never try to open executable files (.apk,.exe) with text editors in the hope of "fixing" them. This is not only useless, but can lead to the launch of malicious code if you accidentally activate a hidden function.
Another common problem is a lack of RAM, and if you have a dozen apps open and you're trying to run a heavy graphics presentation, the system can just kill the opening process. Close the background tasks before you work on large documents.
Also worth checking permissions. The reading app must have access to Memory or Files and Media. Without that permission, it will not be physically able to read data from the disk, even if the file format is familiar to it. You can check this in Settings → Apps → [Your app] → Permissions.