Open File Manager And Complete Midiag.apk Installation. Then Try Again Online

How to Fix the "Open File Manager and Complete Midiag.apk Installation" Error

If you are trying to update your system, install a custom ROM, or run a specific diagnostic tool on your Android device, you might have encountered a stubborn popup that says:

"Open file manager and complete midiag.apk installation. then try again"

This error can be frustrating because it often loops or appears without a clear way to resolve it. You might click "OK," look through your files, and find... nothing. How to Fix the "Open File Manager and Complete Midiag

Don't worry. This is a known issue, usually related to system diagnostic tools or specific manufacturer skins (like some MiUI versions or custom ROMs). Here is a step-by-step guide on what this error means and how to fix it.

Solution 5: The Third-Party ROM Fix

If you are using a custom ROM (like LineageOS or a ported ROM from another device), midiag.apk might be a leftover file causing conflict. "Open file manager and complete midiag

  1. Connect your phone to a PC or use a root-enabled file explorer.
  2. Search the entire system for midiag.apk.
  3. If you find it in a temporary folder (like /data/local/tmp or /tmp), delete it.
  4. If the file does not exist at all, try downloading a generic midiag.apk from a trusted forum (like XDA Developers) specifically for your device model, manually install it, and then reboot.

Fix A: Clear Cache of Package Installer

  1. Go to Settings → Apps → Manage apps.
  2. Tap the three-dot menu → Show system services.
  3. Search for Package Installer or Google Package Installer.
  4. Tap Clear cache and Clear data.
  5. Reboot your phone and try again.

Step 2: Enable “Install from Unknown Sources”

Before you can install the APK, you must allow your file manager (or the browser used to download the file) to install unknown apps.

On Android 8.0 - 12:

  1. Go to Settings → Apps & notifications (or just Apps).
  2. Tap the three dots or Advanced → Special app access → Install unknown apps.
  3. Find your file manager app (e.g., “Files by Google”).
  4. Toggle Allow from this source to ON.

On Android 13/14:

  1. Settings → Security & Privacy → More security settings (or Install unknown apps directly).
  2. Tap your file manager app.
  3. Enable Allow app installs.

Alternatively, when you first try to open an APK, Android will ask for permission. Grant it then. This error can be frustrating because it often

Solution 3: Check for Pending Updates

This error often pops up on devices (particularly Xiaomi/Redmi/Poco devices running MIUI) during system updates. The system might be trying to install a diagnostic update alongside a major Android update.

  1. Go to Settings > System Updates (or MIUI Updates).
  2. Check if there is a pending update. Sometimes you might see an exclamation mark or a notification that an update "failed."
  3. Tap to Retry or Resume the update.
  4. If an update is available, complete it. This usually installs the missing midiag.apk correctly automatically.