gradle: Execution failed for task ':myApp:processDebugManifest' - android-studio

Question

I have am really stumped...
I have an Android Studio (version 1.4) project consisting of two modules - androidLVL and myApp. When I attempt to build the project (Build -> Rebuild Project) I get these messages:
:myApp:processDebugManifest FAILED
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':myApp:processDebugManifest'.
> java.lang.NullPointerException (no error message)
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
BUILD FAILED
Previous answers to this question indicate the error can be caused by incompatible sdk version numbers in the gradle build files - but I can't figure out what the correct versions should be. I edited the build files, but to no avail. Can someone please help? Here are the two gradle build files:
androidLVL:
apply plugin: 'com.android.library'
android {
// compileSdkVersion 22
compileSdkVersion 'Google Inc.:Google APIs:8'
buildToolsVersion "21.1.2"
defaultConfig {
minSdkVersion 10
targetSdkVersion 22
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
}
}
productFlavors {
}
}
dependencies {
compile 'com.google.android.gms:play-services:4.2.42'
compile 'com.android.support:appcompat-v7:22.0.+'
}
myApp:
apply plugin: 'com.android.application'
android {
compileSdkVersion 'Google Inc.:Google APIs:8'
buildToolsVersion "21.1.2"
defaultConfig {
applicationId "com.tomoreilly.myApp"
minSdkVersion 10
targetSdkVersion 22
compileSdkVersion 22
}
buildTypes {
release {
minifyEnabled true
proguardFiles 'proguard-android.txt', 'proguard-project.txt'
}
}
}
dependencies {
compile project(':androidLVL')
compile files('libs/acra-4.2.3.jar')
compile files('libs/htmllexer.jar')
// compile "com.android.support:appcompat-v7:21.0.3"
compile 'com.google.android.gms:play-services:8.1.0'
compile 'com.google.android.gms:play-services-ads:8.1.0'
compile 'com.google.android.gms:play-services-identity:8.1.0'
compile 'com.google.android.gms:play-services-gcm:8.1.0'
}
(Re the error message suggestion to 'run with --stacktrace option' etc. - I do not know how to invoke these options from within Android Studio).