"CommandInvokationFailure: Gradle build failed" when building to Android

I’m trying to build a test program to Android just to see if it works (I only have one blank scene) and I keep getting this error:

CommandInvokationFailure: Gradle build failed.
C:/Program Files/Java/jdk-9.0.1\bin\java.exe -classpath “C:\Program Files\Unity\Editor\Data\PlaybackEngines\AndroidPlayer\Tools\gradle\lib\gradle-launcher-4.0.1.jar” org.gradle.launcher.GradleMain “-Dorg.gradle.jvmargs=-Xmx2048m” “assembleRelease”

jdk… use earlier version!