This bug was originally marked as duplicate of bug 244651, that is already resolved. This bug is still valid, so this seems to be another bug, but it might be related.

Build: NetBeans IDE 8.2 (Build 201705191307)
VM: Java HotSpot(TM) 64-Bit Server VM, 25.131-b11, Java(TM) SE Runtime Environment, 1.8.0_131-b11
OS: Windows 10

User Comments:
GUEST: Create a new Crodova Hellow World project, attempt to run project while Android Emulator is running.

GUEST: Tried running cordova application

GUEST: Run freshly made Cordova project

GUEST: Tried to run a cordova project

GUEST: Impossible to debug in emulator or device(android)

GUEST: set android_home variable environment

alexsmarquez: Hello, whats up!
 I was running an application demo when the problem happening, occur before appear the content in android emulator, and don't initiates emulation.

GUEST: OK

GUEST: Create a new Oracle JET sample application
Run project to android device

GUEST: trying to run a cordova android application.

SDK is installed and using commandline to build and deploy to android works.
Just does not work with netbeans.

GUEST: Attempting to deploy a cordova app on the (running) Android Emulator

GUEST: Tried to build cordova application for android

GUEST: it does not run the Cordova application

GUEST: Building a Cordova app to device

GUEST: I was trying to run the Cordova (Android Emulator). My Android Emulator was running before I ran my project.




Stacktrace: 
java.lang.NullPointerException
   at java.util.Hashtable.put(Hashtable.java:459)
   at org.netbeans.modules.cordova.platforms.android.AndroidDevice.addProperties(AndroidDevice.java:184)
   at org.netbeans.modules.cordova.CordovaPerformer.properties(CordovaPerformer.java:374)
   at org.netbeans.modules.cordova.CordovaPerformer.access$200(CordovaPerformer.java:96)
   at org.netbeans.modules.cordova.CordovaPerformer$1.run(CordovaPerformer.java:228)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1443)