android - LayoutInflate Exception with ViewPager -

java.lang.runtimeexception: unable start activity componentinfo{urlinq.android.com.edu_chat_lollipop/urlinq.android.com.edu_chat.loginactivity}: android.view.inflateexception: binary xml file line #10: binary xml file line #10: error inflating class android.support.v4.view.viewpager 

still getting message after reinstalling android studio. not sure going on here got message after updating minsdk version.

i have user using same files , application able run. fragment runs viewpager. have red exclamation mark next background on viewpager defined in activity.

private viewpager mviewpager; private pageradapter mcustompageradapter; private imagebutton signupbtntoggle; private imagebutton loginbtntoggle; private imagebutton loginbtn;  @override public void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate); }  @override /**  * load login_main.xml layout.  * in addition, load viewpager.  */ public view oncreateview(layoutinflater inflater, viewgroup container, bundle savedinstancestate) {     //initialize viewpager object.     view v = inflater.inflate(r.layout.login_main, container, false);     mviewpager = (viewpager) v.findviewbyid(r.id.loginpager);     mviewpager.setadapter(new loginadapter(getactivity().getsupportfragmentmanager()));       final layerdrawable background = (layerdrawable) mviewpager.getbackground();      background.getdrawable(0).setalpha(0);     //lowest drawable     background.getdrawable(1).setalpha(0);     background.getdrawable(2).setalpha(1); //outermost drawable.      mviewpager.setpagetransformer(true, new viewpager.pagetransformer() {         @override         public void transformpage(view view, float position) {             int index = (integer) view.gettag();             drawable currentdrawableinlayerdrawable;             currentdrawableinlayerdrawable = background.getdrawable(index);             // change visibility of each of fragment layers when swiping left , right.              if (position <= -1 || position >= 1) {                 currentdrawableinlayerdrawable.setalpha(0);             } else if (position == 0) {                 currentdrawableinlayerdrawable.setalpha(255);             } else {                 currentdrawableinlayerdrawable.setalpha((int) (255 - math.abs(position * 255)));             }         }     });      return v; } 

login_drawable.xml

    <?xml version="1.0" encoding="utf-8"?> <layer-list  xmlns:android="http://schemas.android.com/apk/res/android">     <item>         <bitmap             android:id="@+id/idofbg3"             android:gravity="fill"             android:src="@drawable/welcome" />     </item>     <item>         <bitmap             android:id="@+id/idofbg2"             android:gravity="fill"             android:src="@drawable/welcome2" />     </item>     <item>         <bitmap             android:id="@+id/idofbg1"             android:gravity="fill"             android:src="@drawable/welcome3" />     </item>  </layer-list> 

build.gradle

    apply plugin: 'com.android.application'  android {     compilesdkversion 23     buildtoolsversion '23.0.1'      defaultconfig {         applicationid "urlinq.android.com.edu_chat_lollipop"         minsdkversion 22         targetsdkversion 23         versioncode 1         versionname "1.0"     }     buildtypes {         release {             minifyenabled false             proguardfiles getdefaultproguardfile('proguard-android.txt'), 'proguard-rules.pro'         }     }      repositories {         maven {             url 'https://oss.sonatype.org/content/repositories/snapshots/'         }     }      dependencies {         compile 'com.loopj.android:android-async-http:1.4.9'     } }  dependencies {     compile filetree(dir: 'libs', include: ['*.jar'])     testcompile 'junit:junit:4.12'     compile 'com.android.support:appcompat-v7:23.0.1'     compile 'com.android.support:design:23.0.1' } 

login_main.xml

<?xml version="1.0" encoding="utf-8"?> <relativelayout xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:tools="http://schemas.android.com/tools"     android:layout_width="match_parent" android:layout_height="match_parent"     android:layout_alignparentleft="true"     android:layout_alignparentright="true"     android:layout_alignparenttop="true">      <android.support.v4.view.viewpager         android:id="@+id/loginpager"         android:layout_width="match_parent"         android:layout_height="340dp"         android:background = "@drawable/login_drawable"         android:layout_alignparentend="true"         android:layout_alignparentstart="true" />      <fragment         android:layout_width="match_parent"         android:layout_height="285dp"         android:name="urlinq.android.com.edu_chat.signupfragment"         android:id="@+id/fragment"         android:layout_alignparentstart="true"         android:layout_alignparentend="true"         tools:layout="@layout/combined_login"         android:layout_alignparentbottom="true" />      <imageview         android:layout_width="150dp"         android:layout_height="65dp"         android:id="@+id/educhatlogo"         android:background="@drawable/chatlogo"         android:layout_alignparenttop="true"         android:layout_centerhorizontal="true"         android:layout_margintop="20dp" />  </relativelayout> 

try add dependencies

compile 'com.android.support:support-v4:23.0.1'