Receving this error after registration

[marmik57]

main java.lang.NullPointerException at com.smartwaysolutions.chatapplication.ui.adapters.UserListingRecyclerAdapter.onBindViewHolder(UserListingRecyclerAdapter.java:37) at com.smartwaysolutions.chatapplication.ui.adapters.UserListingRecyclerAdapter.onBindViewHolder(UserListingRecyclerAdapter.java:15) at android.support.v7.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:6356) at android.support.v7.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:6389) at android.support.v7.widget.RecyclerView$Recycler.tryBindViewHolderByDeadline(RecyclerView.java:5335) at android.support.v7.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:5598) at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5440) at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5436) at android.support.v7.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:2224) at android.support.v7.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1551) at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1511) at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:595) at android.support.v7.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3583) at android.support.v7.widget.RecyclerView.dispatchLayout(RecyclerView.java:3312) at android.support.v7.widget.RecyclerView.onLayout(RecyclerView.java:3844) at android.view.View.layout(View.java:13836) at android.view.ViewGroup.layout(ViewGroup.java:4380) at android.support.v4.widget.SwipeRefreshLayout.onLayout(SwipeRefreshLayout.java:636) at android.view.View.layout(View.java:13836) at android.view.ViewGroup.layout(ViewGroup.java:4380) at android.widget.FrameLayout.onLayout(FrameLayout.java:448) at android.view.View.layout(View.java:13836) at android.view.ViewGroup.layout(ViewGroup.java:4380) at android.support.v4.view.ViewPager.onLayout(ViewPager.java:1795) at android.view.View.layout(View.java:13836) at android.view.ViewGroup.layout(ViewGroup.java:4380) at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1649) at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1507) at android.widget.LinearLayout.onLayout(LinearLayout.java:1420) at android.view.View.layout(View.java:13836) at android.view.ViewGroup.layout(ViewGroup.java:4380) at android.support.design.widget.HeaderScrollingViewBehavior.layoutChild(HeaderScrollingViewBehavior.java:131) at android.support.design.widget.ViewOffsetBehavior.onLayoutChild(ViewOffsetBehavior.java:42) at android.support.design.widget.AppBarLayout$ScrollingViewBehavior.onLayoutChild(AppBarLayout.java:1391) at android.support.design.widget.CoordinatorLayout.onLayout(CoordinatorLayout.java:870) at android.view.View.layout(View.java:13836) at android.view.ViewGroup.layout(ViewGroup.java:4380) at android.widget.FrameLayout.onLayout(FrameLayout.java:448) at android.view.View.layout(View.java:13836) at android.view.ViewGroup.layout(ViewGroup.java:4380) at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1649) at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1507) at android.widget.LinearLayout.onLayout(LinearLayout.java:1420) at android.view.View.layout(View.java:13836) at android.view.ViewGroup.layout(ViewGroup.java:4380) at android.widget.FrameLayout.onLayout(FrameLayout.java:448) at android.view.View.layout(View.java:13836) at android.view.ViewGroup.layout(ViewGroup.java:4380) at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1649) at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1507) at android.widget.LinearLayout.onLayout(LinearLayout.java:1420) at android.view.View.layout(View.java:13836) at android.view.ViewGroup.layout(ViewGroup.java:4380) at android.widget.FrameLayout.onLayout(FrameLayout.java:448) at android.view.View.layout(View.java:13836) at android.view.ViewGroup.layout(ViewGroup.java:

[WaqasAzamKml]

The code i'm posting is not the optimal solution, but it'll handle this error. Update your onBindViewHolder inside UserListingRecyclerAdapter.java file

@Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        User user = mUsers.get(position);
        String alphabet;
        if(user.email!=null) {
            alphabet = user.email.substring(0, 1);
            holder.txtUsername.setText(user.email);
            holder.txtUserAlphabet.setText(alphabet);
        }
        else {
            alphabet = "n";
            holder.txtUsername.setText("[email protected]");
            holder.txtUserAlphabet.setText(alphabet);
        }

    }