java - Android Studio runtime error: Class not found using the boot class loader -

i'm new android studio , i've been trying run app "ev515" doesn't run on tablet , logcat shows me following message:

caused by: java.lang.noclassdeffounderror: class not found using boot class loader; no stack available

here's mainactivity far:

public class mainactivity extends activity {  private final string tag = "ev515"; private int samplerate; private int energy; private int amplitude; private int buffer[]; private button statusbutton; private button inputinfobutton; private button argsbutton; private button loadbutton; private button recbutton; private button runbutton; private button plotbutton; private button resetbutton; private textview status; private textview info; private textview args; private float time = 0.0f; private double elapsed = 0.0d; private string filename; private string filepath; private double f0min; private double f0max; private double framelength; private double timestep; private double evthreads; private double pthr1; private double fftthreads; private double fftpower;  @override protected void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.menu.menu_main);     actionbar actionbar = getactionbar();     actionbar.setbackgrounddrawable(new colordrawable(color.blue));     actionbar.show(); } // when app opens  @override public boolean oncreateoptionsmenu(menu menu) {     // inflate menu; adds items action bar if present.     getmenuinflater().inflate(r.menu.menu_main, menu);     return super.oncreateoptionsmenu(menu); } // inflates action bar (menu)  @override public boolean onoptionsitemselected(menuitem item) {     // handle action bar item clicks here. action bar     // automatically handle clicks on home/up button, long     // specify parent activity in androidmanifest.xml.     intent intent;     switch (item.getitemid()) {         case r.id.action_settings: // when settings button clicked             intent = new intent(this, settingsactivity.class);             return true;         case r.id.action_information: // when info button clicked             intent = new intent(this, infoactivity.class);             return true;         default:             return super.onoptionsitemselected(item);     } } // assigns tasks buttons on actions bars  protected void onstart() {   super.onstart();     sharedpreferences evsettings = this.getsharedpreferences("ev_settings", 0);     if(evsettings.getboolean("usedefaults", true)) {         this.f0min = 50.0d;         this.f0max = 600.0d;         this.framelength = 0.06d;         this.timestep = 0.01d;         this.pthr1 = 2.0d;     } else {         this.f0min = double.parsedouble(evsettings.getstring("f0min", "50"));         this.f0max = double.parsedouble(evsettings.getstring("f0max", "600"));         this.framelength = double.parsedouble(evsettings.getstring("framelength", "0.06"));         this.timestep = double.parsedouble(evsettings.getstring("timestep", "0.01"));         this.pthr1 = double.parsedouble(evsettings.getstring("pthr1", "2"));     }      if(evsettings.getboolean("usebest", true)) {         double intent = (double)runtime.getruntime().availableprocessors();         this.evthreads = 2.0d * math.floor(math.sqrt(intent));         this.fftthreads = 2.0d * math.floor(2.0d * intent / this.evthreads);         this.fftpower = 13.0d;     } else {         this.evthreads = double.parsedouble(evsettings.getstring("evthreads", "2"));         this.fftthreads = double.parsedouble(evsettings.getstring("fftthreads", "2"));         this.fftpower = double.parsedouble(evsettings.getstring("fftpower", "13"));     }      this.args.settext("f0 min = " + string.format("%.0f", new object[]{double.valueof(this.f0min)}) + " hz\n" + "f0 max = "             + string.format("%.0f", new object[]{double.valueof(this.f0max)}) + " hz\n" + "frame length = "             + string.format("%.2f", new object[]{double.valueof(this.framelength)}) + " seconds\n" + "time step = "             + string.format("%.2f", new object[]{double.valueof(this.timestep)}) + " seconds\n" + "pthr1 = "             + string.format("%.2f", new object[]{double.valueof(this.pthr1)}) + "\n" + "number of ev threads = "             + string.format("%.0f", new object[]{double.valueof(this.evthreads)}) + "\n" + "number of fft threads = "             + string.format("%.0f", new object[]{double.valueof(this.fftthreads)}) + "\n" + "total number of threads = "             + string.format("%.0f", new object[]{double.valueof(this.evthreads * this.fftthreads)}) + "\n" + "fft size = "             + string.format("%.0f", new object[]{double.valueof(math.pow(2.0d, this.fftpower))}) + "\n");     if(this.time != 0.0f & this.framelength > (double)this.time) {         toast.maketext(this, "error: ev frame length argument greater audio total duration, please choose " +                 "a value smaller " + string.format("%.2f", new object[]{float.valueof(this.time)})                 + " seconds.", 1).show();         intent intent1 = new intent(this, settingsactivity.class);         this.startactivity(intent1);     }  } // sets preferences according user's inputs in "settings activity"  protected void ondestroy() {     super.onstop();     file tempfile = new file(this.getcachedir() + "/temp.pcm");     file inputfile = new file(this.getcachedir() + "/temp.txt");      if(tempfile.exists()) {         tempfile.delete();     }      if(inputfile.exists()) {         inputfile.delete();     } } // deletes temp text files when app stopped  public void onclick_load(view view) {     intent = new intent(this, filebrowser.class);     this.startactivityforresult(i, 1); } // opens filebrowser when load button clicked  public void onclick_rec(view view) {     intent = new intent(this, recordactivity.class);     this.startactivityforresult(i, 1); } // opens recordactivity when record button clicked } 

here's logcat:

07-14 14:37:37.329    4900-4900/? i/art﹕ late-enabling -xcheck:jni 07-14 14:37:37.356    4900-4910/? i/art﹕ debugger no longer active 07-14 14:37:37.414    4900-4900/? d/androidruntime﹕ shutting down vm     --------- beginning of crash 07-14 14:37:37.417    4900-4900/? e/androidruntime﹕ fatal exception: main     process: edu.rochester.ece.ev515, pid: 4900     java.lang.runtimeexception: unable start activity componentinfo{edu.rochester.ece.ev515/edu.rochester.ece.ev515.mainactivity}: android.view.inflateexception: binary xml file line #1: error inflating class menu             @ android.app.activitythread.performlaunchactivity(activitythread.java:2325)             @ android.app.activitythread.handlelaunchactivity(activitythread.java:2387)             @ android.app.activitythread.access$800(activitythread.java:151)             @ android.app.activitythread$h.handlemessage(activitythread.java:1303)             @ android.os.handler.dispatchmessage(handler.java:102)             @ android.os.looper.loop(looper.java:135)             @ android.app.activitythread.main(activitythread.java:5254)             @ java.lang.reflect.method.invoke(native method)             @ java.lang.reflect.method.invoke(method.java:372)             @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:903)             @ com.android.internal.os.zygoteinit.main(zygoteinit.java:698)      caused by: android.view.inflateexception: binary xml file line #1: error inflating class menu             @ android.view.layoutinflater.createviewfromtag(layoutinflater.java:757)             @ android.view.layoutinflater.inflate(layoutinflater.java:482)             @ android.view.layoutinflater.inflate(layoutinflater.java:414)             @ android.view.layoutinflater.inflate(layoutinflater.java:365)             @ com.android.internal.policy.impl.phonewindow.setcontentview(phonewindow.java:378)             @ android.app.activity.setcontentview(activity.java:2145)             @ edu.rochester.ece.ev515.mainactivity.oncreate(mainactivity.java:85)             @ android.app.activity.performcreate(activity.java:5990)             @ android.app.instrumentation.callactivityoncreate(instrumentation.java:1106)             @ android.app.activitythread.performlaunchactivity(activitythread.java:2278)             at android.app.activitythread.handlelaunchactivity(activitythread.java:2387)             at android.app.activitythread.access$800(activitythread.java:151)             at android.app.activitythread$h.handlemessage(activitythread.java:1303)             at android.os.handler.dispatchmessage(handler.java:102)             at android.os.looper.loop(looper.java:135)             at android.app.activitythread.main(activitythread.java:5254)             at java.lang.reflect.method.invoke(native method)             at java.lang.reflect.method.invoke(method.java:372)             at com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:903)             at com.android.internal.os.zygoteinit.main(zygoteinit.java:698)      caused by: java.lang.classnotfoundexception: didn't find class "android.view.menu" on path: dexpathlist[[zip file "/data/app/edu.rochester.ece.ev515-2/base.apk"],nativelibrarydirectories=[/vendor/lib, /system/lib]]             @ dalvik.system.basedexclassloader.findclass(basedexclassloader.java:56)             @ java.lang.classloader.loadclass(classloader.java:511)             @ java.lang.classloader.loadclass(classloader.java:469)             @ android.view.layoutinflater.createview(layoutinflater.java:571)             @ android.view.layoutinflater.oncreateview(layoutinflater.java:665)             @ com.android.internal.policy.impl.phonelayoutinflater.oncreateview(phonelayoutinflater.java:65)             @ android.view.layoutinflater.oncreateview(layoutinflater.java:682)             @ android.view.layoutinflater.createviewfromtag(layoutinflater.java:741)             at android.view.layoutinflater.inflate(layoutinflater.java:482)             at android.view.layoutinflater.inflate(layoutinflater.java:414)             at android.view.layoutinflater.inflate(layoutinflater.java:365)             at com.android.internal.policy.impl.phonewindow.setcontentview(phonewindow.java:378)             at android.app.activity.setcontentview(activity.java:2145)             at edu.rochester.ece.ev515.mainactivity.oncreate(mainactivity.java:85)             at android.app.activity.performcreate(activity.java:5990)             at android.app.instrumentation.callactivityoncreate(instrumentation.java:1106)             at android.app.activitythread.performlaunchactivity(activitythread.java:2278)             at android.app.activitythread.handlelaunchactivity(activitythread.java:2387)             at android.app.activitythread.access$800(activitythread.java:151)             at android.app.activitythread$h.handlemessage(activitythread.java:1303)             at android.os.handler.dispatchmessage(handler.java:102)             at android.os.looper.loop(looper.java:135)             at android.app.activitythread.main(activitythread.java:5254)             at java.lang.reflect.method.invoke(native method)             at java.lang.reflect.method.invoke(method.java:372)             at com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:903)             at com.android.internal.os.zygoteinit.main(zygoteinit.java:698)     suppressed: java.lang.classnotfoundexception: android.view.menu             @ java.lang.class.classforname(native method)             @ java.lang.bootclassloader.findclass(classloader.java:781)             @ java.lang.bootclassloader.loadclass(classloader.java:841)             @ java.lang.classloader.loadclass(classloader.java:504)             ... 25 more      caused by: java.lang.noclassdeffounderror: class not found using boot class loader; no stack available 

and here's manifest

<?xml version="1.0" encoding="utf-8"?> 

<uses-sdk     android:minsdkversion="14"     android:targetsdkversion="19" />  <uses-permission android:name="android.permission.internet" /> <uses-permission android:name="android.permission.access_network_state" /> <uses-permission android:name="android.permission.write_external_storage" /> <uses-permission android:name="android.permission.get_accounts" /> <uses-permission android:name="android.permission.use_credentials" /> <uses-permission android:name="android.permission.access_coarse_location" />  <application     android:allowbackup="true"     android:icon="@mipmap/ic_launcher"     android:label="@string/app_name"     android:theme="@style/apptheme" >     <activity         android:name=".mainactivity"         android:label="@string/app_name" >         <intent-filter>             <action android:name="android.intent.action.main" />              <category android:name="android.intent.category.launcher" />         </intent-filter>     </activity>      <activity         android:name=".filebrowser"         android:label="@string/title_file_chooser" >         <intent-filter>             <action android:name="android.intent.action.main" />              <category android:name="android.intent.category.launcher" />         </intent-filter>     </activity>      <activity         android:name=".infoactivity"         android:label="@string/action_info" >         <intent-filter>             <action android:name="android.intent.action.main" />              <category android:name="android.intent.category.launcher" />         </intent-filter>     </activity>      <activity         android:name=".recordactivity"         android:label="@string/title_activity_record" >         <intent-filter>             <action android:name="android.intent.action.main" />              <category android:name="android.intent.category.launcher" />         </intent-filter>     </activity>      <activity         android:name=".settingsactivity"         android:label="@string/action_settings" >         <intent-filter>             <action android:name="android.intent.action.main" />              <category android:name="android.intent.category.launcher" />         </intent-filter>     </activity> </application>