s anyone aware of InvocationTargetException in POI (being used for reading excel sheets).It is a very strange problem. I have a swing based application which is reading excel sheets. Using this application an excel sheet is selected and processed. After teh same excel sheet is selected and processed a few times, it starts giving InvocationTargetException. If I copy the content from excel sheet and put it into another exel sheet and use that sheet, the problem disappears. It again comes after that excel sheet is processed a few times. The exception is thrown in the part of code which creates a workbook.