Cannot Build for Android

Hi,

I have been trying to build for Android for the past 7 hours and every suggested solution for similar errors I have tried doesn't work.

The errors I am getting are:

CommandInvokationFailure: Failed to build apk. C:/Program Files/Java/jdk-9\bin\java.exe -Xmx2048M -Dcom.android.sdkmanager.toolsdir="C:\Users\USERNAME\AppData\Local\Android\Sdk\tools" -Dfile.encoding=UTF8 -jar "C:\Program Files\Unity\Editor\Data\PlaybackEngines\AndroidPlayer/Tools\sdktools.jar" -

and

UnityEditor.BuildPlayerWindow+BuildMethodException: Build failed with errors. at UnityEditor.BuildPlayerWindow+DefaultBuildMethods.BuildPlayer (BuildPlayerOptions options) [0x001b9] in C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindowBuildMethods.cs:162 at UnityEditor.BuildPlayerWindow.CallBuildMethods (Boolean askForBuildLocation, BuildOptions defaultBuildOptions) [0x00050] in C:\buildslave\unity\build\Editor\Mono\BuildPlayerWindowBuildMethods.cs:83 UnityEditor.HostView:OnGUI()

Given the " (Boolean askForBuildLocation, BuildOptions defaultBuildOptions) [0x00050] " part of the second error, I have tried saving my apk to other directories, desktop, C:, Documents, nothing makes a difference.

Anyone know what is going on here?

My SDK and JDK are both up to date. Any help would be really appreciated.

Thanks.