Invalid initial content for document

Hi, I’m using Bonita Studio Community version 7.8.4.
In a project, I create an instantiation form and it works correctly until I added a document in Data tab and set initial content for it from contract. Just I set initial content for my document variable, below error is showing in validation status or when I run the project:
Invalid initial content for document reqDocument. No FILE contract input has been found.
When I’m going to edit document, file Contract input is cleared! I adding it again but still the problem exist!

The problem is solved!
I used “Add data from …” inside of “Add” in contract tab and added document variable by it.

adding contract data

If i have correctly understand, you have added a new element in your contract named ‘reqDocument’ ?
*reqDocument *need to be a **File **type.
So if this error happend, you just need to add this on your ‘init form’ in your 'formOutput var ( that’s the default name in Bonita).
like that:
{
myContractVarName:18,
reqDocument: myDocument,

}

Yeah, I added it , but the error is exist . Actually defining initial content for document to cause error. initialize content for document is required that get data from init form.