android - Unity: Admob Reward Video Ad Doesn't Call Events -

i'm trying add admob reward video ad android game made in unity. displays fine when close ad, reward never given. i've tested code in function , works fine think problem is isn't gettting called. can me?

using unityengine; using unityengine.ui; using system.collections; using system; using googlemobileads; using googlemobileads.api;  public class textedit : monobehaviour {    public image lifeadui;    static image lifeaduistat;    public text adfailui;    static text adfailuistat;    public button lifebutton;     private static rewardbasedvideoad videoad;    static bool adtime = false;    static bool adplaying = false;    static int pass = 0;    bool watched;    // use initialisation   void start()   {     button btn = lifebutton.getcomponent<button>();     btn.onclick.addlistener(videoad);      videoad = rewardbasedvideoad.instance;      videoad.onadfailedtoload += handleonadfailedtoload;     videoad.onadopening += handleonadopening;     videoad.onadclosed += handleonadclosed;     videoad.onadrewarded += handleonadreward;     videoad.onadleavingapplication += handleonadleavingapplication;     videoad.onadloaded += handleonadloaded;     videoad.onadstarted += handleonadstarted;      lifeaduistat = lifeadui;     adfailuistat = adfailui;    }   public static void loadvideoad() { #if unity_editor     string adunitid = "unused"; #elif unity_android     string adunitid = "ca-app-pub-3025391748532285/9122766975"; #elif unity_iphone     string adunitid = ""; #else     string adunitid = "unexpected_platform"; #endif       videoad.loadad(new adrequest.builder().build(), adunitid);     pass = pass + 1;  }  void videoad() {     if (videoad.isloaded())     {         videoad.show();       }     else     {         //ad not loaded     } }  //ad events public void handleonadfailedtoload(object sender, adfailedtoloadeventargs args) {     if (pass < 2)     {         loadvideoad();     }     else     {         startcoroutine(adfailcoro());     } }   public void handleonadopening(object ssender, eventargs args)  {     adplaying = true;  }   public void handleonadclosed(object sender, eventargs args)  {     adplaying = false;     watched = true;      if (watched == true)     {         control controlscript = gameobject.findgameobjectwithtag("control").getcomponent<control>();          lifeadui.enabled = false;         startcoroutine(controlscript.extralife());     }  }   public void handleonadreward(object sender, eventargs args)  {     watched = true;  }   public void handleonadleavingapplication(object sender, eventargs args)  {    }    public void handleonadloaded(object sender, eventargs args)   {    }    public void handleonadstarted(object sender, eventargs args)   {    } } 

if called videoad show video ad due unforeseen reason video not loaded yet, or having loading failure, request load ad again.

void videoad() {     if (videoad.isloaded())     {         videoad.show();     }     else     {         loadvideoad();     } } 

request load new video ad when ad closed user.

public void handleonadclosed(object sender, eventargs args) {     adplaying = false;     watched = true;      if (watched == true)  //what need of condition, true      {         control controlscript = gameobject.findgameobjectwithtag("control").getcomponent<control>();          lifeadui.enabled = false;         startcoroutine(controlscript.extralife());         loadvideoad();     }  }