Before we dive into the installation process, let's briefly discuss what Midiag.apk is. Midiag.apk is an Android application package file that contains the MIUI Diagnostic tool, a built-in app on Xiaomi devices that allows users to perform diagnostic tests on their device. However, if you're a user of a non-Xiaomi device or want to use the app on a device that doesn't have it pre-installed, you'll need to manually install the Midiag.apk file.

Here's a step-by-step guide on how to open File Manager and complete the Midiag.apk installation:

The "Open File Manager And Complete Midiag.apk Installation" prompt usually appears when you're trying to install an APK file (like Midiag.apk) on your Android device. By default, Android devices have a security feature that prevents the installation of APK files from unknown sources. To bypass this restriction, you'll need to access the File Manager app to complete the installation.