RecordFormatException

["Natu, Ashlesha [IT]" <as...@citigroup.com>]

Hi,
 
I am using POI to read an excel spreadsheet which is uploaded by the user through the browser. The code saves this file on the server and reads it. The code can read the data fine. But if I modify something in the file and then upload it, I get the following exception:
 
org.apache.poi.hssf.record.RecordFormatException: Unable to construct record instance, the following exception occured: null
 
But, if after modifying, I re-format all the columns, save it , upload it, then the code works fine and reads the excel file. Many columns in the excel file have drop down list boxes in them. Why do I have to re-format all the columns every time I modify something?
 
Can anyone please help?
 
thanks & regards,
Ashlesha Natu
(908)563-0802