I am new to Android programming and running on version 3.6.3. I am having a Build failed: error 1; XML document must start and end with the same entity.
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="androidx.constraintlayout.widget"> //This one is errorTagged with "Element manifest must be declaired."
<uses-sdk android:minSdkVersion="9" //This one is tagged with "Tag start is not closed" but when I close it with '/>', it changes to 'Unexpected ending.'```