XLS to XLSX conversion - an exception occurred in .NET


I am trying to convert an excel file from .XLS to .XLSX with the code below.

Workbook wb = new Workbook(file);
wb.Save("new_format_file.xlsx", SaveFormat.Xlsx);

It can covert 10,000+ files, except for one file in the attachment below.
aa.zip (308.3 KB)

Could you tell me how to fix or the limitation for converting file?

Best Regards,
Chokchai L,


We will evaluate your issue and get back to you soon.

We have reproduced the issue and logged it in our database for further investigation. You will be notified here once any update is ready for sharing.

This issue is logged as:
CELLSNET-48062 - Exception raised while converting XLS to XLSX

This is to inform you that we have fixed your issue now. We will soon provide you the fixed version after performing QA and incorporating other enhancements and fixes.

Please try the latest fix 21.5.1.
Aspose.Cells21.5.1 For .Net2_AuthenticodeSigned.Zip (5.5 MB)
Aspose.Cells21.5.1 For .Net4.0.Zip (5.5 MB)
Aspose.Cells21.5.1 For .NetStandard20.Zip (5.5 MB)

Hi Simon,

Thank you for your support. I will test and let you know the result asap.


Please take your time to test the new fix. Hopefully your issue will be fixed in it.

Dear Amjad,

Version 21.5.1 resolved this issue. Thank you for you great support.

Will this version be available in NuGet anytime soon?

Best Regards,

Chokchai L,


Good to know that your issue is resolved. Aspose.Cells for .NET 21.6 will be published on NuGet around 3rd week of June. We will notify you once it will be released.

The issues you have found earlier (filed as CELLSNET-48062) have been fixed in this update. This message was posted using Bugs notification tool by simon.zhao

1 Like