java.lang.IllegalStateException: Report from Google Developer Console

Question

So I have my application published in the Play Store and it seems like some of my users are facing crashes. I am trying to reproduce it to get logs, but not able not so stuck with the error log provided by Google.

But I am honestly not able to understand the issue here from the log so need your help!

Crash Log

java.lang.IllegalStateException: 
  at android.support.v4.app.Fragment.requireContext (Fragment.java:614)
  at android.support.v4.app.Fragment.getResources (Fragment.java:678)
  at com.tinyapps.newsly.providers.priceticker.currencydetails.chartandtable.GraphFragment.lambda$getCMCChart$0$GraphFragment (GraphFragment.java:243)
  at com.tinyapps.newsly.providers.priceticker.currencydetails.chartandtable.GraphFragment$$Lambda$0.onTaskCompleted (Unknown Source:8)
  at com.grizzly.rest.GenericRestCall.afterCall (GenericRestCall.java:1054)
  at com.grizzly.rest.GenericRestCall.onPostExecute (GenericRestCall.java:1030)
  at com.grizzly.rest.GenericRestCall.onPostExecute (GenericRestCall.java:55)
  at android.os.AsyncTask.finish (AsyncTask.java:695)
  at android.os.AsyncTask.-wrap1 (Unknown Source)
  at android.os.AsyncTask$InternalHandler.handleMessage (AsyncTask.java:712)
  at android.os.Handler.dispatchMessage (Handler.java:106)
  at android.os.Looper.loop (Looper.java:164)
  at android.app.ActivityThread.main (ActivityThread.java:6753)
  at java.lang.reflect.Method.invoke (Native Method)
  at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run (RuntimeInit.java:482)
  at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:807)

Code Of this Fragment

public class GraphFragment extends Fragment implements OnChartValueSelectedListener {

    private int chartFillColor;
    private int chartBorderColor;
    private String cryptoID;
    private int percentageColor;
    private LineChart lineChart;
    private View rootView;
    private CustomViewPager viewPager;
    private IAxisValueFormatter XAxisFormatter;
    public final IAxisValueFormatter monthSlashDayXAxisFormatter = new MonthSlashDayDateFormatter();
    public final TimeDateFormatter dayCommaTimeDateFormatter = new TimeDateFormatter();
    public final MonthSlashYearFormatter monthSlashYearFormatter = new MonthSlashYearFormatter();
    private String currentTimeWindow = "";
    private SingleSelectToggleGroup buttonGroup;
    public static String CURRENT_CHART_URL;
    public final static DecimalFormat rawNumberFormat = new DecimalFormat("#,###.##");
    private LockableNestedScrollView nestedScrollView;
    private int displayWidth;
    private ProgressBar chartProgressBar;
    private String tsymbol;
    private CurrencyFormatterSingleton currencyFormatter;
    private SharedPreferences sharedPreferences;
    NumberFormat chartUSDPriceFormat = NumberFormat.getInstance();
    SimpleDateFormat fullDateFormat = new SimpleDateFormat("EEE, d MMM yyyy HH:mm:ss z", Locale.ENGLISH);

    public static final String SHAREDPREF_SETTINGS = "newsly_settings";
    public static final String CHART_SPINNER_SETTING = "chart_spinner_setting";
    public static final String ARG_SYMBOL = "symbol";
    public static final String ARG_ID = "ID";
    public static final String COIN_OBJECT = "COIN_OBJECT";

    public GraphFragment() {
    }

    /**
     * Returns a new instance of this fragment for the given section
     * number.
     */
    public static GraphFragment newInstance(String symbol, String id) {
        GraphFragment fragment = new GraphFragment();
        Bundle args = new Bundle();
        args.putString(ARG_SYMBOL, symbol);
        args.putString(ARG_ID, id);
        fragment.setArguments(args);
        return fragment;
    }

    public void setColors(float percentChange) {
        if (percentChange >= 0) {
            chartFillColor = ResourcesCompat.getColor(getActivity().getResources(), R.color.materialLightGreen, null);
            chartBorderColor = ResourcesCompat.getColor(getActivity().getResources(), R.color.darkGreen, null);
            percentageColor = ResourcesCompat.getColor(getActivity().getResources(), R.color.percentPositiveGreen, null);
        }
        else {
            chartFillColor = ResourcesCompat.getColor(getActivity().getResources(), R.color.materialLightRed, null);
            chartBorderColor = ResourcesCompat.getColor(getActivity().getResources(), R.color.darkRed, null);
            percentageColor = ResourcesCompat.getColor(getActivity().getResources(), R.color.percentNegativeRed, null);
        }
    }

    public void setUpChart() {
        XAxis xAxis = lineChart.getXAxis();
        xAxis.setDrawAxisLine(false);
        xAxis.setPosition(XAxis.XAxisPosition.BOTTOM_INSIDE);
        xAxis.setAvoidFirstLastClipping(false);
        lineChart.getAxisLeft().setEnabled(true);
        lineChart.getAxisLeft().setDrawGridLines(true);
        lineChart.getAxisLeft().setTextColor(Color.WHITE);
        lineChart.getXAxis().setTextColor(Color.WHITE);
        lineChart.getXAxis().setDrawGridLines(true);
        lineChart.getAxisRight().setEnabled(false);
        lineChart.getLegend().setTextColor(Color.WHITE);
        lineChart.getLegend().setEnabled(false);
        lineChart.setDoubleTapToZoomEnabled(false);
        lineChart.setScaleEnabled(false);
        lineChart.getDescription().setEnabled(false);
        lineChart.setContentDescription("");
        lineChart.setNoDataText(getString(R.string.noChartDataString));
        lineChart.setNoDataTextColor(R.color.darkRed);
        lineChart.setOnChartValueSelectedListener(this);
        lineChart.setOnChartGestureListener(new OnChartGestureListener() {
            @Override
            public void onChartGestureStart(MotionEvent me, ChartTouchListener.ChartGesture lastPerformedGesture) {
                YAxis yAxis = lineChart.getAxisLeft();
                // Allow scrolling in the right and left margins
                if (me.getX() > yAxis.getLongestLabel().length() * yAxis.getTextSize() &&
                        me.getX() < displayWidth - lineChart.getViewPortHandler().offsetRight()) {
                    viewPager.setPagingEnabled(false);
                    nestedScrollView.setScrollingEnabled(false);
                }
            }

            @Override
            public void onChartGestureEnd(MotionEvent me, ChartTouchListener.ChartGesture lastPerformedGesture) {
                viewPager.setPagingEnabled(true);
                nestedScrollView.setScrollingEnabled(true);
            }

            @Override
            public void onChartLongPressed(MotionEvent me) {

            }

            @Override
            public void onChartDoubleTapped(MotionEvent me) {

            }

            @Override
            public void onChartSingleTapped(MotionEvent me) {

            }

            @Override
            public void onChartFling(MotionEvent me1, MotionEvent me2, float velocityX, float velocityY) {

            }

            @Override
            public void onChartScale(MotionEvent me, float scaleX, float scaleY) {

            }

            @Override
            public void onChartTranslate(MotionEvent me, float dX, float dY) {

            }
        });
    }

    public LineDataSet setUpLineDataSet(List<Entry> entries) {
        LineDataSet dataSet = new LineDataSet(entries, "Price");
        dataSet.setColor(chartBorderColor);
        dataSet.setFillColor(chartFillColor);
        dataSet.setDrawFilled(true);
        dataSet.setDrawCircles(false);
        dataSet.setCircleColor(chartBorderColor);
        dataSet.setDrawCircleHole(false);
        dataSet.setDrawValues(true);
        dataSet.setValueTextColor(getResources().getColor(R.color.white));
        dataSet.setHighLightColor(getResources().getColor(R.color.white));
        dataSet.setCircleRadius(1);
        dataSet.setHighlightLineWidth(2);
        dataSet.setHighlightEnabled(false);
        dataSet.setDrawHighlightIndicators(false);
        dataSet.setHighLightColor(chartBorderColor); // color for highlight indicator
        return dataSet;
    }

    public void getCMCChart() {
        final TextView percentChangeText = rootView.findViewById(R.id.percent_change);
        final TextView currPriceText = rootView.findViewById(R.id.current_price);
        currPriceText.setTextColor(getResources().getColor(R.color.white));
        lineChart.setEnabled(true);
        lineChart.clear();
        chartProgressBar.setVisibility(View.VISIBLE);
        CoinMarketCapService.getCMCChartData(getActivity(), cryptoID, cmcChartData -> {
            List<Entry> closePrices = new ArrayList<>();
            if (tsymbol.equals("USD")) {
                for (List<Float> priceTimeUnit : cmcChartData.getPriceUSD()) {
                    closePrices.add(new Entry(priceTimeUnit.get(0), priceTimeUnit.get(1)));
                }
            } else {
                for (List<Float> priceTimeUnit : cmcChartData.getPriceBTC()) {
                    closePrices.add(new Entry(priceTimeUnit.get(0), priceTimeUnit.get(1)));
                }
            }
            if (closePrices.size() == 0) {
                lineChart.setData(null);
                lineChart.setEnabled(false);
                lineChart.invalidate();
                percentChangeText.setText("");
                currPriceText.setText("");
                lineChart.setNoDataText(getResources().getString(R.string.noChartDataString));
                chartProgressBar.setVisibility(View.GONE);
                return;
            }
            XAxis xAxis = lineChart.getXAxis();
            xAxis.setValueFormatter(XAxisFormatter);
           // TextView currentPriceTextView = rootView.findViewById(R.id.current_price);
            float currPrice = closePrices.get(closePrices.size() - 1).getY();
            TextView chartDateTextView = rootView.findViewById(R.id.graphFragmentDateTextView);
            chartDateTextView.setText(getFormattedFullDate(closePrices.get(closePrices.size() - 1).getX()));
            if (tsymbol.equals("USD")) {
                currPriceText.setText(String.format(getResources().getString(R.string.unrounded_usd_chart_price_format), String.valueOf(currPrice)));
            } else {
                currPriceText.setText(currencyFormatter.format(currPrice, "BTC"));
            }
            currPriceText.setTextColor(Color.WHITE);
            float firstPrice = closePrices.get(0).getY();
            // Handle edge case where we dont have data for the interval on the chart. E.g. user selects
            // 3 month window, but we only have data for last month
            for (Entry e: closePrices) {
                if (firstPrice != 0) {
                    break;
                } else {
                    firstPrice = e.getY();
                }
            }
            float difference = (currPrice - firstPrice);
            float percentChange = (difference / firstPrice) * 100;
            if (percentChange < 0) {
                if (tsymbol.equals("USD")) {
                    percentChangeText.setText(String.format(getResources().getString(R.string.negative_variable_pct_change_with_dollars_format), currentTimeWindow, percentChange, Math.abs(difference)));
                } else {
                    percentChangeText.setText(String.format(getResources().getString(R.string.negative_variable_pct_change_without_dollars_format), currentTimeWindow, percentChange));
                }
            } else {
                if (tsymbol.equals("USD")) {
                    percentChangeText.setText(String.format(getResources().getString(R.string.positive_variable_pct_change_with_dollars_format), currentTimeWindow, percentChange, Math.abs(difference)));
                } else {
                    percentChangeText.setText(String.format(getResources().getString(R.string.positive_variable_pct_change_without_dollars_format), currentTimeWindow, percentChange));
                }
            }
            setColors(percentChange);
            percentChangeText.setTextColor(percentageColor);
            LineDataSet dataSet = setUpLineDataSet(closePrices);
            LineData lineData = new LineData(dataSet);
            lineChart.setData(lineData);
            lineChart.animateX(800);
            chartProgressBar.setVisibility(View.GONE);
        }, new afterTaskFailure() {
            @Override
            public void onTaskFailed(Object o, Exception e) {
                Log.e("ERROR", "Server Error: " + e.getMessage());
                lineChart.setNoDataText(getString(R.string.noChartDataString));
                chartProgressBar.setVisibility(View.GONE);
            }
        }, true);
    }

    public void setDayChecked(Calendar cal) {
        long endTime = cal.getTimeInMillis();
        cal.add(Calendar.DAY_OF_YEAR, -1);
        long startTime = cal.getTimeInMillis();
        cal.clear();
        CURRENT_CHART_URL = String.format(COIN_MARKETCAP_CHART_URL_WINDOW, cryptoID, startTime, endTime);
        currentTimeWindow = getString(R.string.oneDay);
        XAxisFormatter = dayCommaTimeDateFormatter;
    }

    public void setWeekChecked(Calendar cal) {
        long endTime = cal.getTimeInMillis();
        cal.add(Calendar.DAY_OF_YEAR, -7);
        long startTime = cal.getTimeInMillis();
        cal.clear();
        CURRENT_CHART_URL = String.format(COIN_MARKETCAP_CHART_URL_WINDOW, cryptoID, startTime, endTime);
        currentTimeWindow = getString(R.string.Week);
        XAxisFormatter = monthSlashDayXAxisFormatter;
    }

    public void setMonthChecked(Calendar cal) {
        long endTime = cal.getTimeInMillis();
        cal.add(Calendar.MONTH, -1);
        long startTime = cal.getTimeInMillis();
        cal.clear();
        CURRENT_CHART_URL = String.format(COIN_MARKETCAP_CHART_URL_WINDOW, cryptoID, startTime, endTime);
        currentTimeWindow = getString(R.string.Month);
        XAxisFormatter = monthSlashDayXAxisFormatter;
    }

    public void setThreeMonthChecked(Calendar cal) {
        long endTime = cal.getTimeInMillis();
        cal.add(Calendar.MONTH, -3);
        long startTime = cal.getTimeInMillis();
        cal.clear();
        CURRENT_CHART_URL = String.format(COIN_MARKETCAP_CHART_URL_WINDOW, cryptoID, startTime, endTime);
        currentTimeWindow = getString(R.string.threeMonth);
        XAxisFormatter = monthSlashDayXAxisFormatter;
    }

    public void setYearChecked(Calendar cal) {
        long endTime = cal.getTimeInMillis();
        cal.add(Calendar.YEAR, -1);
        long startTime = cal.getTimeInMillis();
        cal.clear();
        CURRENT_CHART_URL = String.format(COIN_MARKETCAP_CHART_URL_WINDOW, cryptoID, startTime, endTime);
        currentTimeWindow = getString(R.string.Year);
        XAxisFormatter = monthSlashYearFormatter;
    }

    public void setAllTimeChecked() {
        currentTimeWindow = getString(R.string.AllTime);
        CURRENT_CHART_URL = String.format(COIN_MARKETCAP_CHART_URL_ALL_DATA, cryptoID);
        XAxisFormatter = monthSlashYearFormatter;
    }

    public void setTable(CMCCoin coinObject, View rootVeiw) {
        String usdFormat = getString(R.string.usd_format);
        String negativePctFormat = getString(R.string.negative_pct_format);
        String positivePctFormat = getString(R.string.positive_pct_format);
        int negativeRedColor = getResources().getColor(R.color.percentNegativeRed);
        int positiveGreenColor = getResources().getColor(R.color.percentPositiveGreen);
        TextView nameTextView = rootVeiw.findViewById(R.id.tableNameDataTextView);
        if (coinObject.getName() == null) {
            nameTextView.setText("N/A");
        } else {
            nameTextView.setText(coinObject.getName());
        }

        TextView priceUSDTextView = rootVeiw.findViewById(R.id.tablePriceUSDDataTextView);
        if (coinObject.getPrice_usd() == null) {
            priceUSDTextView.setText("N/A");
        } else {
            priceUSDTextView.setText(String.format(usdFormat, Double.parseDouble(coinObject.getPrice_usd())));
        }

        TextView priceBTCTextView = rootVeiw.findViewById(R.id.tablePriceBTCDataTextView);
        if (coinObject.getPrice_btc() == null) {
            priceBTCTextView.setText("N/A");
        } else {
            priceBTCTextView.setText(String.format(getString(R.string.btc_format), coinObject.getPrice_btc()));
        }

        TextView volumeTextView = rootVeiw.findViewById(R.id.tableVolUSDDataTextView);
        if (coinObject.getVolume_usd_24h() == null) {
            volumeTextView.setText("N/A");
        } else {
            volumeTextView.setText(String.format(usdFormat, Double.parseDouble(coinObject.getVolume_usd_24h())));
        }

        TextView mktCapTextView = rootVeiw.findViewById(R.id.tableMktCapDataTextView);
        if (coinObject.getMarket_cap_usd() == null) {
            mktCapTextView.setText("N/A");
        } else {
            mktCapTextView.setText(String.format(usdFormat, Double.parseDouble(coinObject.getMarket_cap_usd())));
        }

        TextView availSupplyTextView = rootVeiw.findViewById(R.id.tableAvailableSupplyDataTextView);
        if (coinObject.getAvailable_supply() == null) {
            availSupplyTextView.setText("N/A");
        } else {
            availSupplyTextView.setText(rawNumberFormat.format(Double.parseDouble(coinObject.getAvailable_supply())));
        }

        TextView totalSupplyTextView = rootVeiw.findViewById(R.id.tableTotalSupplyDataTextView);
        if (coinObject.getTotal_supply() == null) {
            totalSupplyTextView.setText("N/A");
        } else {
            totalSupplyTextView.setText(rawNumberFormat.format(Double.parseDouble(coinObject.getTotal_supply())));
        }

        TextView maxSupplyTextView = rootVeiw.findViewById(R.id.tableMaxSupplyDataTextView);
        if (coinObject.getMax_supply() == null) {
            maxSupplyTextView.setText("N/A");
        } else {
            maxSupplyTextView.setText(rawNumberFormat.format(Double.parseDouble(coinObject.getMax_supply())));
        }

        TextView oneHrChangeTextView = rootVeiw.findViewById(R.id.table1hrChangeDataTextView);
        if (coinObject.getPercent_change_1h() == null) {
            oneHrChangeTextView.setText("N/A");
        } else {
            double amount = Double.parseDouble(coinObject.getPercent_change_1h());
            if (amount >= 0) {
                oneHrChangeTextView.setText("Change 1h\n" +String.format(positivePctFormat, amount));
                oneHrChangeTextView.setTextColor(positiveGreenColor);
            } else {
                oneHrChangeTextView.setText("Change 1h\n" +String.format(negativePctFormat, amount));
                oneHrChangeTextView.setTextColor(negativeRedColor);
            }
        }

        TextView dayChangeTextView = rootVeiw.findViewById(R.id.table24hrChangeDataTextView);
        if (coinObject.getPercent_change_24h() == null) {
            dayChangeTextView.setText("N/A");
        } else {
            double amount = Double.parseDouble(coinObject.getPercent_change_24h());
            if (amount >= 0) {
                dayChangeTextView.setText("Change 24h\n" +String.format(positivePctFormat, amount));
                dayChangeTextView.setTextColor(positiveGreenColor);
            } else {
                dayChangeTextView.setText("Change 24h\n" +String.format(negativePctFormat, amount));
                dayChangeTextView.setTextColor(negativeRedColor);
            }
        }

        TextView weekChangeTextView = rootVeiw.findViewById(R.id.tableWeekChangeDataTextView);
        if (coinObject.getPercent_change_7d() == null) {
            weekChangeTextView.setText("N/A");
        } else {
            double amount = Double.parseDouble(coinObject.getPercent_change_7d());
            if (amount >= 0) {
                weekChangeTextView.setText("Change 7d\n" +String.format(positivePctFormat, amount));
                weekChangeTextView.setTextColor(positiveGreenColor);
            } else {
                weekChangeTextView.setText("Change 7d\n" +String.format(negativePctFormat, amount));
                weekChangeTextView.setTextColor(negativeRedColor);
            }
        }
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        rootView = inflater.inflate(R.layout.fragment_graph, container, false);
        lineChart = rootView.findViewById(R.id.chart);
        chartUSDPriceFormat = NumberFormat.getInstance();
        chartUSDPriceFormat.setMaximumFractionDigits(10);
        setUpChart();
        currencyFormatter = CurrencyFormatterSingleton.getInstance(getContext());
       // WindowManager mWinMgr = (WindowManager) getActivity().getSystemService(Context.WINDOW_SERVICE);
       // displayWidth = mWinMgr.getDefaultDisplay().getWidth();
        chartProgressBar = rootView.findViewById(R.id.chartProgressSpinner);
        // Button sourceButton = rootView.findViewById(R.id.sourceButton);
        // sourceButton.setPaintFlags(sourceButton.getPaintFlags() | Paint.UNDERLINE_TEXT_FLAG);
        sharedPreferences = getContext().getSharedPreferences(SHAREDPREF_SETTINGS, MODE_PRIVATE);
        Spinner chartCurrencySelector = rootView.findViewById(R.id.chartCurrencySelectSpinnr);

        final ArrayAdapter<String> spinnerArrayAdapter = new ArrayAdapter<String>(getContext(), R.layout.spinner_item, getResources().getStringArray(R.array.chart_spinner_options));
        spinnerArrayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

        tsymbol = sharedPreferences.getString(CHART_SPINNER_SETTING, "USD");
        chartCurrencySelector.setAdapter(spinnerArrayAdapter);
        if (tsymbol.equals("USD")) {
            chartCurrencySelector.setSelection(0);
        } else {
            chartCurrencySelector.setSelection(1);
        }
        chartCurrencySelector.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
               // ((TextView) chartCurrencySelector.getSelectedView()).setTextColor(Color.WHITE);
                tsymbol = spinnerArrayAdapter.getItem(position);
                SharedPreferences.Editor editor = sharedPreferences.edit();
                editor.putString(CHART_SPINNER_SETTING, tsymbol);
                editor.apply();
                getCMCChart();
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {
            }
        });

        viewPager = (CustomViewPager) container;
        nestedScrollView = rootView.findViewById(R.id.graphFragmentNestedScrollView);
        buttonGroup = rootView.findViewById(R.id.chart_interval_button_grp);
        cryptoID = getArguments().getString(ARG_ID);
        setDayChecked(Calendar.getInstance());
        buttonGroup.check(R.id.dayButton);
        currentTimeWindow = getString(R.string.oneDay);
        // sourceButton.setOnClickListener(new View.OnClickListener() {
        //     @Override
        //     public void onClick(View v) {
        //         CustomTabsIntent.Builder builder = new CustomTabsIntent.Builder();
        //         CustomTabsIntent customTabsIntent = builder.build();
        //         customTabsIntent.launchUrl(getActivity(), Uri.parse(BASE_CMC_SOURCE_URL + cryptoID));
        //     }
        // });
        buttonGroup.setOnCheckedChangeListener((group, checkedId) -> {
            Calendar.getInstance();
            switch (checkedId) {
                case R.id.dayButton:
                    setDayChecked(Calendar.getInstance());
                    getCMCChart();
                    break;
                case R.id.weekButton:
                    setWeekChecked(Calendar.getInstance());
                    getCMCChart();
                    break;
                case R.id.monthButton:
                    setMonthChecked(Calendar.getInstance());
                    getCMCChart();
                    break;
                case R.id.threeMonthButton:
                    setThreeMonthChecked(Calendar.getInstance());
                    getCMCChart();
                    break;
                case R.id.yearButton:
                    setYearChecked(Calendar.getInstance());
                    getCMCChart();
                    break;
                case R.id.allTimeButton:
                    setAllTimeChecked();
                    getCMCChart();
                    break;
            }
        });
        CMCCoin coinObject = getActivity().getIntent().getParcelableExtra(GraphFragment.COIN_OBJECT);
        setTable(coinObject, rootView);
        return rootView;
    }

    // test commit

    @Override
    public void onValueSelected(Entry e, Highlight h) {
        TextView currentPrice = rootView.findViewById(R.id.current_price);
        currentPrice.setTextColor(getResources().getColor(R.color.myTextPrimaryColor));
        TextView dateTextView = rootView.findViewById(R.id.graphFragmentDateTextView);
        if (tsymbol.equals("USD")) {
            currentPrice.setText(String.format(getString(R.string.unrounded_usd_chart_price_format), String.valueOf(e.getY())));
        } else {
            currentPrice.setText(currencyFormatter.format(e.getY(), "BTC"));
        }
        dateTextView.setText(getFormattedFullDate(e.getX()));
    }

    @Override
    public void onNothingSelected() {

    }

    public String getFormattedFullDate(float unixSeconds) {
        Date date = new Date((long)unixSeconds);
        return fullDateFormat.format(date);
    }
}

Thank you, looking forward to getting some help!

Edit: As per the docs, IllegalStateException error is occurred when the code is repeated, at least that's what my understanding is but my code has nothing repeated.

Answer 1

Usually, IllegalStateException is used to indicate that "a method has been invoked at an illegal or inappropriate time." However, this doesn't look like a particularly typical use of it.

https://docs.oracle.com/javase/8/docs/api/index.html?java/lang/IllegalStateException.html

Illegal State Exception is an Unchecked exception. It indicate that method has been invoked at wrong time.

Example :

Thread t = new Thread();
t.start();
//
//
t.start();

We can not start the Thread again, it will throw IllegalStateException.

Answer 2

this can be prevented ...

public void getCMCChart() {
    if(getActivity() != null) {
       ...
    }
}

getResources() assumes that the Fragment is attached to an instance of Context - which results in an IllegalStateException , when the method is being called during the illegal state of !isAttached() . one could also check with getContext() != null or with isAttached() .