Error occurred while converting Excel document to PDF format

We are facing an issue with a excel when converting to PDF. It returns below error:

There is an Error while converting attachment in PDF format. Exception :- Error occurred while converting Excel document to PDF format .
System.ArgumentNullException: Value cannot be null.
Parameter name: input
at System.Text.RegularExpressions.Regex.IsMatch(String input)
at System.Text.RegularExpressions.Regex.IsMatch(String input, String pattern)
at ?? . (?? )
at ?? .(?? )
at ?? .(String , Chart )
at ?? .()
at .(? , String , ?? )
at .(? , String , ?? )
at .(?? )
at .()
at .(Workbook , LoadOptions )
at Aspose.Cells.Workbook.(Stream , LoadOptions , Boolean )Aspose.zip (40.6 KB)

@KanishkaRai,

I can not reproduce ArgumentNullException while converting attached XLSB file to PDF with Aspose.Cells for .NET 18.8. Please share your code snippet with us for our testing with latest version of API.

We are using version 11.6 currently, can this be issue?

Is it possible to upgrade to the latest version under same license?

@KanishkaRai,

Yes, this can be an issue or limitation with the older version you are using. We recommend you to kindly upgrade to and use latest version of the product (e.g Aspose.cells for .NET v18.8.x). In newer versions, we have made support and added enhancements for parsing and rendering Ms Excel 2016 charts. Moreover, I do not think your current license could be used with latest version, your license might have expired to use newer versions, so you may upgrade your subscription. For confirmation if you license is expired or not, please open your license file into notepad (please do not modify your license least it won’t work anymore) and check subscription expiry date.