Run-time exception when running simple unit test with Powermock (with mockito) on Android Studio

I've got a run-time error when I try to run my Unit tests in Android Studio, that I just can't seem to solve. I'm guessing it's something to do with the dependencies since the error trace doesn't specify any of my unit testing code.

My app.gradle file looks like:

dependencies {
    testCompile 'org.mockito:mockito-core:1.10.19'
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:23.0.1'
    testCompile 'junit:junit:4.12'
    testCompile 'org.powermock:powermock-api-mockito:1.6.3'
    testCompile 'org.powermock:powermock-module-junit4-rule-agent:1.6.3'
    testCompile 'org.powermock:powermock-module-junit4-rule:1.6.3'
    testCompile 'org.powermock:powermock-module-junit4:1.6.3' }

The error i'm getting looks like:

java.lang.RuntimeException: Invoking the beforeTestMethod method on PowerMock test listener org.powermock.api.extension.listener.AnnotationEnabler@38d8f54a failed.
at org.powermock.tests.utils.impl.PowerMockTestNotifierImpl.notifyBeforeTestMethod(PowerMockTestNotifierImpl.java:92)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.executeTest(PowerMockJUnit44RunnerDelegateImpl.java:292)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTestInSuper(PowerMockJUnit47RunnerDelegateImpl.java:127)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTest(PowerMockJUnit47RunnerDelegateImpl.java:82)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runBeforesThenTestThenAfters(PowerMockJUnit44RunnerDelegateImpl.java:282)
at org.junit.internal.runners.MethodRoadie.runTest(MethodRoadie.java:87)
at org.junit.internal.runners.MethodRoadie.run(MethodRoadie.java:50)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.invokeTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:207)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.runMethods(PowerMockJUnit44RunnerDelegateImpl.java:146)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$1.run(PowerMockJUnit44RunnerDelegateImpl.java:120)
at org.junit.internal.runners.ClassRoadie.runUnprotected(ClassRoadie.java:34)
at org.junit.internal.runners.ClassRoadie.runProtected(ClassRoadie.java:44)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.run(PowerMockJUnit44RunnerDelegateImpl.java:122)
at org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.run(JUnit4TestSuiteChunkerImpl.java:106)
at org.powermock.modules.junit4.common.internal.impl.AbstractCommonPowerMockRunner.run(AbstractCommonPowerMockRunner.java:53)
at org.powermock.modules.junit4.PowerMockRunner.run(PowerMockRunner.java:59)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:78)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:212)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:68)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140) 


Caused by: java.lang.IllegalArgumentException: Cannot subclass final class class [[I
at org.mockito.cglib.proxy.Enhancer.generateClass(Enhancer.java:447)
at org.mockito.cglib.core.DefaultGeneratorStrategy.generate(DefaultGeneratorStrategy.java:25)
at org.mockito.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:217)
at org.mockito.cglib.proxy.Enhancer.createHelper(Enhancer.java:378)
at org.mockito.cglib.proxy.Enhancer.createClass(Enhancer.java:318)
at org.powermock.api.mockito.repackaged.ClassImposterizer.createProxyClass(ClassImposterizer.java:123)
at org.powermock.api.mockito.repackaged.ClassImposterizer.imposterise(ClassImposterizer.java:57)
at org.powermock.api.mockito.internal.mockcreation.MockCreator.createMethodInvocationControl(MockCreator.java:111)
at org.powermock.api.mockito.internal.mockcreation.MockCreator.mock(MockCreator.java:59)
at org.powermock.api.mockito.PowerMockito.mock(PowerMockito.java:203)
at org.powermock.api.extension.listener.AnnotationEnabler.standardInject(AnnotationEnabler.java:106)
at org.powermock.api.extension.listener.AnnotationEnabler.beforeTestMethod(AnnotationEnabler.java:54)
at org.powermock.tests.utils.impl.PowerMockTestNotifierImpl.notifyBeforeTestMethod(PowerMockTestNotifierImpl.java:90)
... 24 more


Process finished with exit code 254    

Any help would be appreciated, thank you!