DS 4.0: Unable to read xlsx

Hi Experts,

We use BusinessObjects Data Services 4.0 SP2 Patch 4, version 14.0.2.409 on Windows 2008 Server.We have created BoExcelAdapter to read Excel source and we were not facing any issues in reading the Excel files so far.

Yesterday when we ran the job to read a new excel file, we received the error message 'Could not find worksheet ... in file ..'.

But the excel file has the specified worksheet.

Could you please guide me as to what has caused such an error and how to resolve this.