聊天页报错

 Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void com.hyphenate.chat.EMConversation.markAllMessagesAsRead()' on a null object reference
                      at com.hyphenate.easeui.ui.EaseChatFragment.onConversationInit(EaseChatFragment.java:370)
                      at com.hyphenate.easeui.ui.EaseChatFragment.setUpView(EaseChatFragment.java:326)
                      at com.hyphenate.easeui.ui.EaseBaseFragment.onActivityCreated(EaseBaseFragment.java:25)
                      at com.hyphenate.easeui.ui.EaseChatFragment.onActivityCreated(EaseChatFragment.java:162)
                      at android.support.v4.app.Fragment.performActivityCreated(Fragment.java:2346)
                      at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1442)
                      at android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManager.java:1740)
                      at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1809)
                      at android.support.v4.app.BackStackRecord.executeOps(BackStackRecord.java:799)
                      at android.support.v4.app.FragmentManagerImpl.executeOps(FragmentManager.java:2580)
                      at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2367)
                      at android.support.v4.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManager.java:2322)
                      at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:2229)
                      at android.support.v4.app.FragmentManagerImpl.dispatchStateChange(FragmentManager.java:3221)
                      at android.support.v4.app.FragmentManagerImpl.dispatchActivityCreated(FragmentManager.java:3171)
                      at android.support.v4.app.FragmentController.dispatchActivityCreated(FragmentController.java:192)
                      at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:552)
                      at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1240)
                      at android.app.Activity.performStart(Activity.java:6268)
                      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2380)
                      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2477) 
                      at android.app.ActivityThread.-wrap11(ActivityThread.java) 
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1345) 
                      at android.os.Handler.dispatchMessage(Handler.java:102) 
                      at android.os.Looper.loop(Looper.java:148) 
                      at android.app.ActivityThread.main(ActivityThread.java:5468) 
                      at java.lang.reflect.Method.invoke(Native Method) 
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:781) 
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:671)