ExternalSystemException when importing gradle project

Hi,
i am currently trying to import a gradle module created with android studio as a java module, because I want to use it as a common backend for a server and client application. 

However, intellij is throwing an exception:

2016-11-14 23:39:15,830 [4170243] WARN - nal.AbstractExternalSystemTask - org.gradle.tooling.model.idea.IdeaModule.getJavaLanguageSettings()Lorg/gradle/tooling/model/idea/IdeaJavaLanguageSettings;
        com.intellij.openapi.externalSystem.model.ExternalSystemException: org.gradle.tooling.model.idea.IdeaModule.getJavaLanguageSettings()Lorg/gradle/tooling/model/idea/IdeaJavaLanguageSettings;
        at org.jetbrains.plugins.gradle.service.execution.GradleExecutionHelper.execute(GradleExecutionHelper.java:225)
        at org.jetbrains.plugins.gradle.service.project.GradleProjectResolver.resolveProjectInfo(GradleProjectResolver.java:112)
        at org.jetbrains.plugins.gradle.service.project.GradleProjectResolver.resolveProjectInfo(GradleProjectResolver.java:72)
        at com.intellij.openapi.externalSystem.service.remote.RemoteExternalSystemProjectResolverImpl.lambda$resolveProjectInfo$0(RemoteExternalSystemProjectResolverImpl.java:37)
        at com.intellij.openapi.externalSystem.service.remote.AbstractRemoteExternalSystemService.execute(AbstractRemoteExternalSystemService.java:59)
        at com.intellij.openapi.externalSystem.service.remote.RemoteExternalSystemProjectResolverImpl.resolveProjectInfo(RemoteExternalSystemProjectResolverImpl.java:37)
        at com.intellij.openapi.externalSystem.service.remote.wrapper.ExternalSystemProjectResolverWrapper.resolveProjectInfo(ExternalSystemProjectResolverWrapper.java:49)
        at com.intellij.openapi.externalSystem.service.internal.ExternalSystemResolveProjectTask.doExecute(ExternalSystemResolveProjectTask.java:51)
        at com.intellij.openapi.externalSystem.service.internal.AbstractExternalSystemTask.execute(AbstractExternalSystemTask.java:138)
        at com.intellij.openapi.externalSystem.service.internal.AbstractExternalSystemTask.execute(AbstractExternalSystemTask.java:124)
        at com.intellij.openapi.externalSystem.util.ExternalSystemUtil$3.execute(ExternalSystemUtil.java:415)
        at com.intellij.openapi.externalSystem.util.ExternalSystemUtil$4.run(ExternalSystemUtil.java:485)
        at com.intellij.openapi.progress.impl.CoreProgressManager$TaskRunnable.run(CoreProgressManager.java:635)
        at com.intellij.openapi.progress.impl.CoreProgressManager$9.run(CoreProgressManager.java:384)
        at com.intellij.openapi.progress.impl.CoreProgressManager$3.run(CoreProgressManager.java:170)
        at com.intellij.openapi.progress.impl.CoreProgressManager.registerIndicatorAndRun(CoreProgressManager.java:494)
        at com.intellij.openapi.progress.impl.CoreProgressManager.executeProcessUnderProgress(CoreProgressManager.java:443)
        at com.intellij.openapi.progress.impl.ProgressManagerImpl.executeProcessUnderProgress(ProgressManagerImpl.java:54)
        at com.intellij.openapi.progress.impl.CoreProgressManager.runProcess(CoreProgressManager.java:155)
        at com.intellij.openapi.application.impl.ApplicationImpl.lambda$null$9(ApplicationImpl.java:548)
        at com.intellij.openapi.application.impl.ApplicationImpl$2.run(ApplicationImpl.java:307)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
        at java.lang.Thread.run(Thread.java:745)

Useful information:
gradle-wrapper.properties of Android Studio project contains the following distributionUrl:

distributionUrl=http\://services.gradle.org/distributions/gradle-2.14.1-all.zip

this is the build.gradle of the common project:

apply plugin: 'java'

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
}

sourceCompatibility = "1.7"
targetCompatibility = "1.7"

this is the build.gradle of the app:

apply plugin: 'com.android.application'

android {
    compileSdkVersion 25
    buildToolsVersion "25.0.0"
    defaultConfig {
        minSdkVersion 19
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:appcompat-v7:25.0.0'
    testCompile 'junit:junit:4.12'
    compile project(path: ':common')
}

What am i doing wrong?