This error occurs when there is mismatch between the file format and its extension. This can be resolved by setting workbook version set to the required version.
· To save a workbook in Excel2003 format, set the workbook version to Excel97to2003 and save the file with extension ‘.xls’ i.e. binary file format.
· To save a workbook in Excel 2007/Excel2010/Excel2013 formats, set the workbook version to Excel2007/Excel2010/Excel2013 respectively and save the file with extension ‘.xlsx’ i.e. open xml file format.
The below code example illustrates the same.
string fileName = Server.MapPath("App_data/Sample.xls");
IWorkbook workbook = application.Workbooks.Open(fileName, ExcelOpenType.Automatic);
IWorksheet sheet = workbook.Worksheets;
workbook.Version = ExcelVersion.Excel2007;
workbook.SaveAs(this.TextBox1.Text + ".xlsx", ExcelSaveType.SaveAsXLS, Response, ExcelDownloadType.PromptDialog, ExcelHttpContentType.Excel2007);
We have provided a sample as per your scenario in the below link for your reference. Kindly try with this and let us know.
Please let us know if you need any clarification.
From: suresh thota [mailto:email@example.com]
Sent: 12/02/2015 01:22 AM
To: Syncfusion Support <firstname.lastname@example.org>
Subject: Re: Syncfusion support community forum 121309, Excel can not able to open the file..., has been updated.
Thank you for your reply.
Yes. I have seen from one the the SyncFusion URL. Its working now.
Thank you very much for your support.