java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.Object android.content.Context.getSystemService(java.lang.String)' on a null object reference
	at android.app.Dialog.<init>(Dialog.java:196)
	at android.app.ColorBaseAlertDialog.<init>(ColorBaseAlertDialog.java:33)
	at android.app.AlertDialog.<init>(AlertDialog.java:208)
	at android.app.AlertDialog.<init>(AlertDialog.java:204)
	at android.app.ProgressDialog.<init>(ProgressDialog.java:112)
	at x4.x0$b$a.onPreExecute(Unknown Source:20)
	at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:715)
	at android.os.AsyncTask.execute(AsyncTask.java:662)
	at x4.x0$b.onClick(Unknown Source:42)
	at android.view.View.performClick(View.java:7257)
	at android.view.View.performClickInternal(View.java:7213)
	at android.view.View.access$3800(View.java:828)
	at android.view.View$PerformClick.run(View.java:27921)
	at android.os.Handler.handleCallback(Handler.java:883)
	at android.os.Handler.dispatchMessage(Handler.java:100)
	at android.os.Looper.loop(Looper.java:237)
	at android.app.ActivityThread.main(ActivityThread.java:7830)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1040)