Full Error Message:
“Error while creating new document. Error message: actionId cannot be blank”

-This error message can happen when generating a document and there is an issue with the document action or document action ID.

Solution: 
Typically this error message means there is a permission issue with the user trying to generate the document. You need to double check if all app users have access to Document Action and Document Requests (if using for automation). User should have at least Read access to these objects. Next make sure this user has authorized the app with their google drive and can refer to this article.