The message "open file manager and complete midiag.apk installation" is a specific instruction often encountered on Xiaomi (MIUI/HyperOS) or other Qualcomm-based Android devices when attempting to enable Diagnostic (Diag) Mode. This mode is used for specialized tasks like IMEI repair, QCN reading/writing, or network troubleshooting via PC software. Understanding the Error
How to Fix: "Open File Manager and Complete midiag.apk Installation"
If you haven't installed apps from outside the Google Play Store before, the system will block the action.
- Open Settings → Apps → Manage apps.
- Tap your file manager (e.g., Files by Google, Mi File Manager, Cx File Explorer).
- Tap Install unknown apps.
- Toggle Allow from this source to ON.
Interrupted Setup: The download finished, but the auto-installer failed to launch. 💡 Pro Tip
Step 1: Locate the MIDIag.apk File
First, you need to find where the file was downloaded. By default, Android saves downloads to: