Hi Xing Zhou,
Thank you so much for the update.
From the above given image the "Parameter name: relation" is used in many places with XlsIO source library, so we are unable to find out the actual cause of the issue at our side.
Please get back to us with the following details to proceed further on this issue.
1.The excel template file which causes the above reported exception
2.Complete stack trace for an exception
3.From which source the excel template was created (XlsIO or Microsoft Excel)?
Please let me know if you have any further clarifications.