NegativeArraySizeException, DataProvider, Excel

I'd like to implement the data from Excel file to different tests depending on the scenario correct data/invalid one, however when I want to get the cell value I get the "NegativeArraySizeException".
The first row has just a title so I don't want to read it, that's why I have the parameters [rows-1].
Could you please indicate what is my mistake?
Thank you

public class SignInTest extends Driver {


@BeforeMethod
public void setUp() {
    Driver.initConfiguration();
}

     public Object[][] getData(String excelPath, String sheetName) {
    
            int rows = excel.getRowCount(sheetName);
            int cols = excel.getColumnCount(sheetName);
    
            Object[][] data = new Object[rows - 1][1];
            excel = new ExcelReader(excelPath);
    
            for (int rowNum = 1; rowNum < rows; rowNum++) {
    
                for (int colNum = 0; colNum < cols; colNum++) {
    
                    data[rowNum - 1][colNum] = excel.getCellData(sheetName, colNum, rowNum);
                }
            }
            return data;
        }
      @DataProvider(name = "credentials")
public Object[][] getCredentials() {


    Object[][] data = getData(excelPath, sheetName);

    return data;
}
    
  @Test(dataProviderClass = DataProviders.class, dataProvider = "credentials")
    public void loginWithCorrectCredentials(String email, String password) {

        HomePageActions hp = new HomePageActions();
        SignInActions sign = new SignInActions();
        DataProviders dp = new DataProviders();
 

        dp.getData(excelPath, "correctData");
        System.out.println("email " + email);
        System.out.println("password " + password);

    }

This function "excel.getRowCount(sheetName)"

On this line:

int rows = excel.getRowCount(sheetName);

Is returning 0 (or possibly null), thus when you do rows-1, you get a number less than zero. I should hope that much is obvious. So the question becomes WHY?

Things to look for in troubleshooting:

• Is the getColumnCount also returning zero? If so, this points to a possible
  error in the worksheet reference.
• Is the sheetName actually correctly being passed into the function?
• Can you insert an explicit value into a specific place on the worksheet? Meaning is that reference working? Throw in a test line and see what happens.
• What happens if you hard set the array to say:
  Object[][] data = new Object100;

My gut is telling me you have an issue with the reference to the worksheet, but without knowing more about your worksheet referencing, it's impossible to know for sure.

I hope some of this points you in the right direction and gets you going. Good luck!