Failed to verify instance (org.apache.poi.ss.formula.ptg.EqualPtg) is a singleton.

[Sanunez]

I get the following error when trying to proguard my code with the suggested rules

2019-05-23 12:01:48.138 24237-24299/omegaonedevelopers.client.omegamaps E/AndroidRuntime: FATAL EXCEPTION: AsyncTask #3
    Process: omegaonedevelopers.client.omegamaps, PID: 24237
    java.lang.RuntimeException: An error occurred while executing doInBackground()
        at android.os.AsyncTask$3.done(AsyncTask.java:354)
        at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:383)
        at java.util.concurrent.FutureTask.setException(FutureTask.java:252)
        at java.util.concurrent.FutureTask.run(FutureTask.java:271)
        at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:245)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
        at java.lang.Thread.run(Thread.java:764)
     Caused by: java.lang.ExceptionInInitializerError
        at org.apache.poi.ss.formula.OperationEvaluatorFactory.evaluate(Unknown Source:0)
        at org.apache.poi.ss.formula.WorkbookEvaluator.evaluateFormula(SourceFile:63)
        at org.apache.poi.ss.formula.WorkbookEvaluator.evaluateAny(SourceFile:12)
        at org.apache.poi.ss.formula.WorkbookEvaluator.evaluate(SourceFile:2)
        at org.apache.poi.xssf.usermodel.BaseXSSFFormulaEvaluator.evaluateFormulaCellValue(SourceFile:2)
        at org.apache.poi.ss.formula.BaseFormulaEvaluator.evaluate(SourceFile:5)
        at omegaonedevelopers.client.omegamaps.MainActivity.a(SourceFile:53)
        at omegaonedevelopers.client.omegamaps.MainActivity.b(SourceFile:2)
        at omegaonedevelopers.client.omegamaps.MainActivity$a.doInBackground(SourceFile:4)
        at android.os.AsyncTask$2.call(AsyncTask.java:333)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:245) 
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167) 
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641) 
        at java.lang.Thread.run(Thread.java:764) 
     Caused by: java.lang.RuntimeException: Failed to verify instance (org.apache.poi.ss.formula.ptg.EqualPtg) is a singleton.
        at org.apache.poi.ss.formula.OperationEvaluatorFactory.put(SourceFile:4)
        at org.apache.poi.ss.formula.OperationEvaluatorFactory.initialiseInstancesMap(SourceFile:2)
        at org.apache.poi.ss.formula.OperationEvaluatorFactory.<clinit>(SourceFile:1)
        at org.apache.poi.ss.formula.OperationEvaluatorFactory.evaluate(Unknown Source:0) 
        at org.apache.poi.ss.formula.WorkbookEvaluator.evaluateFormula(SourceFile:63) 
        at org.apache.poi.ss.formula.WorkbookEvaluator.evaluateAny(SourceFile:12) 
        at org.apache.poi.ss.formula.WorkbookEvaluator.evaluate(SourceFile:2) 
        at org.apache.poi.xssf.usermodel.BaseXSSFFormulaEvaluator.evaluateFormulaCellValue(SourceFile:2) 
        at org.apache.poi.ss.formula.BaseFormulaEvaluator.evaluate(SourceFile:5) 
        at omegaonedevelopers.client.omegamaps.MainActivity.a(SourceFile:53) 
        at omegaonedevelopers.client.omegamaps.MainActivity.b(SourceFile:2) 
        at omegaonedevelopers.client.omegamaps.MainActivity$a.doInBackground(SourceFile:4) 
        at android.os.AsyncTask$2.call(AsyncTask.java:333) 
        at java.util.concurrent.FutureTask.run(FutureTask.java:266) 
        at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:245) 
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167) 
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641) 
        at java.lang.Thread.run(Thread.java:764) 

When running to get this code

private String getCellValue(FormulaEvaluator evaluator, Cell cell){
        String cellString = "";
        try {
            CellValue cellValue = evaluator.evaluate(cell);
            if(cellValue != null){
                switch (cellValue.getCellType()) {
                    case Cell.CELL_TYPE_BOOLEAN:
                        cellString = Boolean.toString(cellValue.getBooleanValue());
                        break;
                    case Cell.CELL_TYPE_NUMERIC:
                        cellString = Double.toString(cellValue.getNumberValue());
                        break;
                    case Cell.CELL_TYPE_STRING:
                        cellString = cellValue.getStringValue();
                        break;
                }
            }
        } catch (Exception e) {
            Log.e(TAG, e.getMessage());
        }
        return cellString;
    }

[centic9]

Sorry, I have only very little knowledge about proguard for Android, so I cannot help much here, except asking you to try to exclude this class from proguard.

Probably some other place for asking questions like stackoverflow may be able to provide some useful answers.