java - App crashes by opening spinner on popup -

i got massive problem spinner. popup appears without problem , it's showing spinner in closed position.

but when open it, app crashes following error message...

04-10 08:34:33.773    1690-1690/com.example.paul_io e/androidruntime﹕ fatal exception: main process: com.example.paul_io, pid: 1690 android.view.windowmanager$badtokenexception: unable add window -- token android.view.viewrootimpl$w@52f02170 not valid; activity running?         @ android.view.viewrootimpl.setview(viewrootimpl.java:532)         @ android.view.windowmanagerglobal.addview(windowmanagerglobal.java:259)         @ android.view.windowmanagerimpl.addview(windowmanagerimpl.java:69)         @ android.widget.popupwindow.invokepopup(popupwindow.java:1019)         @ android.widget.popupwindow.showasdropdown(popupwindow.java:925)         @ android.widget.listpopupwindow.show(listpopupwindow.java:625)         @ android.widget.spinner$dropdownpopup.show(spinner.java:1110)         @ android.widget.spinner.performclick(spinner.java:658)         @ android.view.view$performclick.run(view.java:18422)         @ android.os.handler.handlecallback(handler.java:733)         @ android.os.handler.dispatchmessage(handler.java:95)         @ android.os.looper.loop(looper.java:136)         @ android.app.activitythread.main(activitythread.java:5001)         @ java.lang.reflect.method.invokenative(native method)         @ java.lang.reflect.method.invoke(method.java:515)         @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:785)         @ com.android.internal.os.zygoteinit.main(zygoteinit.java:601)         @ dalvik.system.nativestart.main(native method) 

what i´ve done wrong?

significant code:

  variables.mainactivity = mainactivity.this; . . .  ​   activity mcontext = variables.mainactivity;   spinner ecb = new spinner(mcontext); 

the problem context passed (badtokenexception).

i think using getapplicationcontext().instead use youractivityname.this passing context