java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.v7.widget.RecyclerView.setLayoutManager

[RishabhRawatAndroid]

05-15 19:55:44.535 25362-25535/com.codingblocks.chatter E/chromium: [ERROR:gl_context_virtual.cc(39)] Trying to make virtual context current without decoder.
05-15 19:55:47.470 25362-25362/com.codingblocks.chatter E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.codingblocks.chatter, PID: 25362
    java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.v7.widget.RecyclerView.setLayoutManager(android.support.v7.widget.RecyclerView$LayoutManager)' on a null object reference
        at com.codingblocks.chatter.RoomsFragment.onCreateView(RoomsFragment.java:71)
        at android.support.v4.app.Fragment.performCreateView(Fragment.java:2248)
        at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1340)
        at android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManager.java:1569)
        at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1636)
        at android.support.v4.app.BackStackRecord.executeOps(BackStackRecord.java:758)
        at android.support.v4.app.FragmentManagerImpl.executeOps(FragmentManager.java:2415)
        at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2201)
        at android.support.v4.app.FragmentManagerImpl.optimizeAndExecuteOps(FragmentManager.java:2155)
        at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:2064)
        at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:718)
        at android.os.Handler.handleCallback(Handler.java:742)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:157)
        at android.app.ActivityThread.main(ActivityThread.java:5571)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:745)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:635)

App crashes when we click the Rooms button in bottom navigation bar.