Incorrect input string

I am working with Aspose.word.
& generating some mail merge documents.
when i am giving a input to following function.

document.MailMerge.Execute(dt)

where dt is object of data table.
it throws exception as Incorrect input string.
my datatable object returning a data.
so,please help me to solve my problem.

Hi
Thanks for your request. Could you please attach your document for testing and provide me sample data? I will investigate the problem and provide you more information.
Best regards.