Exception in thread "main" java.lang.NoClassDefFoundError: junit/textui/ResultPrinter

I'm trying to compile my Android project in Android Studio 0.3.0. Today I get the following error:

Exception in thread "main" java.lang.NoClassDefFoundError: junit/textui/ResultPrinter
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:188)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:113)
Caused by: java.lang.ClassNotFoundException: junit.textui.ResultPrinter
at java.net.URLClassLoader$1.run(URLClassLoader.java:217)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
at java.lang.ClassLoader.loadClass(ClassLoader.java:321)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)
at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
... 3 more

Process finished with exit code 1

Doing some web searches leads me to believe this issue is somehow related to JUnit. However, I'm not using JUnit in my project. Maybe I've inadvertently turned on some option? In that case, how do I disable unit testing in my project? Any ideas?

Finally found it. It's in the Run/Debug Configurations dialog. Disabled JUnit and it compiles again.

Usually this problem is caused because of wrong test type: Junit instead of Android Test

For standard JUnit tests, you are missing the JUnit library, try adding this in build.gradle:

dependencies {
    ...
    testCompile 'junit:junit:4.12'
    ...
}

And make sure you are putting the tests in the "test" directory parallell to the "main" package (instrumentation tests goes into "androidTest", but that is different setup).

Force the project to "sync" via menu: Tools > Android > Sync Project with Gradle Files or force the project to "sync" by making a fake change in build.gradle file (add a space and then delete it and then click "sync now").

In my Run/Debug Configurations I had MyTest under AndroidTests and under JUnitTests. The MyTest under AndroidTests was configured correctly, but I still got 'NoClassDefFoundError: junit/textui/ResultPrinter' error. Clicked on MyTest under JUnit and pressed '-' in upper left. This allowed MyTest to run through the device got rid of error.

I've twice had this issue after changing some build.gradle plugins and dependencies around.

Simply turning Android Studio off and on again fixed it for me (versions 2.1.2 and 2.2).

All the answers are good-

Make sure you have sourceSets have the test directory registered.

android{
    ...

    defaultConfig {
         ...
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }

    
    sourceSets {
        androidTest {
            java.srcDirs = ['src/androidTest/java']
        }
    }
}

dependencies{
    ... 
    androidTestCompile 'junit:junit:4.12'
    androidTestCompile 'com.android.support.test:runner:0.5'
}

Just putting the solution which worked for me, this should be tried if you are setting up the environment for first time:

For windows:

1. in the environment variables add a new "system variables" ANDROID_SDK_HOME=D:\Program Files\android-sdk-windows (select your home directory of android sdk )

2. modify system variables Path, add "%Android_SDK_HOME%\tools;"