I am trying to insert a Shared Formula into an existing Excel sheet. every time I open the finished Excel, it shows me an error and fixes the Excel. I have the code from OpenXML Productivity Tools. All other formulas work without problems ...
var cellFormula141 = new CellFormula
{
FormulaType = CellFormulaValues.Shared,
Reference = $"J{rowIndex}",
SharedIndex = 0U,
Text = $"CONCATENATE(MONTH(I{rowIndex}),\"/\",YEAR(I{rowIndex}))"
};
var cellValue215 = new CellValue
{
Text = ""
};
cell372.Append(cellFormula141);
cell372.Append(cellValue215);
Every time I open the excel it is fixed and the formula is gone.