XLSX Template Data Validation Error


I’m trying to create a new XLSX document from Template in Microsoft Flow, passing in data entered in Microsoft Forms. However, everytime I run the flow, I get the following error:

“code”: “Plumsail.Actions.Api.DTO.Exceptions.DataValidationException”,
“message”: "The input is not a valid Base-64 string as it contains a non-base 64 character, more than two padding characters, or an illegal character among the padding characters. ",
“date”: “2019-06-13T01:01:20.9832523Z”

My input fields in the excel template are as follows:

and this is what is being inputted (pulled from other data):
“quantity”: 24,
“invoicenumber”: “PURE2019-06-136738”,
“date”: “Wednesday, June 12, 2019”,

When I run this, the output is a status code (400), and the error message.
I’m not sure what I’m doing wrong, and what the base-64 error is referring to. I tried removing all non base-64 characters from my inputs and that didn’t fix the problem either.

Any help would be appreciated!


Hello @psramani,

Please share with me the flow screenshot in edit mode with details and the excel template. I’ll try to reproduce the issue on my side.

Best regards,
Petr Bushuev
Plumsail team


Hi Petr!
Thanks for your reply - please see the images below

Could I email you or direct message the excel template?



Hello @psramani,

Yes please send it to [email protected] with a reference to the topic.

Best regards,
Petr Bushuev
Plumsail team


Sent! Thank you for your assistance!


Hello @psramani,

I’ll post the solution here as well. It’s turned out to be that template data and document content were placed in wrong fields in the action. We put the JSON to Template data field and the template data to Document content field, it’s fixed the issue.


Best regards,
Petr Bushuev
Plumsail team