ListView initially adding to it works, but if I back track and try adding again I get a error

I am new to android programming and I have been getting bug in my code for the last day or so.

When I run my live chat I can send and read messages as intended, but when I back track to the page that shows my list of conversations and click back into the live chat and resend a message my app crashes with the error below. Why is that? How do I fix it?

java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.Object android.content.Context.getSystemService(java.lang.String)' on a null object reference
        at android.view.LayoutInflater.from(LayoutInflater.java:282)
        at android.widget.ArrayAdapter.<init>(ArrayAdapter.java:213)
        at android.widget.ArrayAdapter.<init>(ArrayAdapter.java:207)
        at android.widget.ArrayAdapter.<init>(ArrayAdapter.java:193)
        at com.example.chatbox4.adapterListLiveChat.<init>(adapterListLiveChat.java:36)
        at com.example.chatbox4.LiveChatFragment$2.onChildAdded(LiveChatFragment.java:131)

RELATED CODE

CHAT FRAGMENT

listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                AppCompatActivity activity=(AppCompatActivity)v.getContext();
                
                activity.getSupportFragmentManager().beginTransaction().replace(R.id.container, new LiveChatFragment(groupId.get(position),groupName.get(position),name,schoolId)).addToBackStack(null).commit();
                groupId.clear();
                groupName.clear();
            }
        });

LIVE CHAT FRAGMENT

data = FirebaseDatabase.getInstance().getReference().child("ChatLogs").child(gid);


data.addChildEventListener(new ChildEventListener() {
            @Override
            //this runs first
            public void onChildAdded(@NonNull DataSnapshot snapshot, @Nullable String previousChildName) {
                showChat(snapshot);
                adapterListLiveChat customList = new adapterListLiveChat(getContext(), liveMessage, ownerName, timePosted,thumbnailUrl,ownerId); //SECOND ERROR ON LINE 131
                list.setAdapter(customList);
            }

            @Override
            public void onChildChanged(@NonNull DataSnapshot snapshot, @Nullable String previousChildName) {
                showChat(snapshot);
                adapterListLiveChat customList = new adapterListLiveChat(getContext(), liveMessage, ownerName, timePosted,thumbnailUrl,ownerId);
                list.setAdapter(customList);
            }

            @Override
            public void onChildRemoved(@NonNull DataSnapshot snapshot) {

            }

            @Override
            public void onChildMoved(@NonNull DataSnapshot snapshot, @Nullable String previousChildName) {

            }

            @Override
            public void onCancelled(@NonNull DatabaseError error) {

            }
        });
        return v;
    }


    private void showChat(DataSnapshot snapshot) {
        Iterator i = snapshot.getChildren().iterator();

        while (i.hasNext()){
            liveMessage.add((String) ((DataSnapshot)i.next()).getValue());
            ownerId.add((String) ((DataSnapshot)i.next()).getValue());
            ownerName.add((String) ((DataSnapshot)i.next()).getValue());
            thumbnailUrl.add((String) ((DataSnapshot)i.next()).getValue());
            timePosted.add((Long) ((DataSnapshot)i.next()).getValue());

        }


    }

CUSTOM ADAPTER FOR LIVE CHAT

public class adapterListLiveChat extends ArrayAdapter{

    ArrayList<String> liveMessage = new ArrayList<String>();
    ArrayList<String> ownerId = new ArrayList<String>();
    ArrayList<String> ownerName = new ArrayList<String>();
    ArrayList<String> thumbnailUrl = new ArrayList<String>();
    ArrayList<Long> timePosted = new ArrayList<Long>();

    Context context;

    public adapterListLiveChat(Context context, ArrayList<String> liveMessage, ArrayList<String> ownerName, ArrayList<Long> timePosted, ArrayList<String> thumbnailUrl, ArrayList<String> ownerId) {
        super(context,R.layout.livechatlayout, ownerName); //FIRST ERROR ON LINE 36
        this.context = context;
        this.liveMessage = liveMessage;
        this.ownerId = ownerId;
        this.ownerName = ownerName;
        this.thumbnailUrl = thumbnailUrl;
        this.timePosted = timePosted;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View row = convertView;
        if(convertView == null){
            LayoutInflater layoutInflater = LayoutInflater.from(context);
            row = layoutInflater.inflate(R.layout.livechatlayout, null);

            TextView userName = (TextView) row.findViewById(R.id.userName);
            TextView message = (TextView) row.findViewById(R.id.textView);
            final ImageView profilePic = (ImageView) row.findViewById(R.id.profilePic);