How do I prevent error messages when I open other people's android studio project?

Question

I am evaluating my fellow coursemate Android Studio project.

WHen I attempt to run, I get the below.

Error message:

Error:A problem occurred configuring project ':app'.
> Could not resolve all dependencies for configuration ':app:_debugCompile'.
   > Could not find com.android.support:appcompat-v7:21.0.3.
     Searched in the following locations:
         https://jcenter.bintray.com/com/android/support/appcompat-v7/21.0.3/appcompat-v7-21.0.3.pom
         https://jcenter.bintray.com/com/android/support/appcompat-v7/21.0.3/appcompat-v7-21.0.3.jar
         file:/Users/kim/Documents/android-sdk-macosx/extras/android/m2repository/com/android/support/appcompat-v7/21.0.3/appcompat-v7-21.0.3.pom
         file:/Users/kim/Documents/android-sdk-macosx/extras/android/m2repository/com/android/support/appcompat-v7/21.0.3/appcompat-v7-21.0.3.jar
     Required by:
         ModernArtUI:app:unspecified

The only way for me to solve the problem is to:

go into their build.gradle (Module: app)

android {
    compileSdkVersion 21
    buildToolsVersion "21.1.2"

and change to

android {
    compileSdkVersion 21
    buildToolsVersion "21.1.1"

and get this:

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:21.0.3'
}

change to

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:21.0.2'
}

How do I avoid having to repeatedly change the build.gradle?

Answer 1

You have to update the repositories with the SDK Manager.

The error shows that gradle didn't find the app compat library 21.0.3 in your extras/android/m2repository (Android Repository).

Launch the sdk manager and update it and the build tools