Failed to resolve: com.android.support:appcompat-v7:25.1.0

My Android Studio is full of error android studio cannot identify libraries.

Error:(27, 13) Failed to resolve: com.android.support:appcompat-v7:25.1.0

Make sure that the repositories section includes a maven section with the "https://maven.google.com" endpoint. For example:

allprojects {
    repositories {
        jcenter()
        maven {
            url "https://maven.google.com"
        }
    }
}

Update:

allprojects {
    repositories {
        google()

        // If you're using a version of Gradle lower than 4.1, you must
        // instead use:
        //
        // maven {
        //     url 'https://maven.google.com'
        // }
    }
}

See android documention for details

There is a problem with latest libraries to be automatically installed by clicking

Install Repository and sync project

Go to SDK Manager and install your missing or not up-to-date packages from below tab:

After you select desired library, click Apply and wait for installation to complete.

Replace whatever build gradle version with this

dependencies {
        classpath 'com.android.tools.build:gradle:3.1.3'
    }

Then Click on

Fix Gradle wrapper and re-import the project

1. At first change your buildToolsVersion version 23.0.1 to 25.0.1
2. Set compileSdkVersion 25

Finally

compileSdkVersion 25
buildToolsVersion "25.0.1"

Make sure you update your support repository . Then Clean-Rebuild-Run.