Failed to construct 'File': Iterator getter is not callable in chrome 60 when use JSON.stringify()

In your case File constructor signature is incorrect, the first argument must be:

An Array of ArrayBuffer, ArrayBufferView, Blob, or DOMString objects — or a mix of any such objects. This is the file content encoded as UTF-8.

https://developer.mozilla.org/en-US/docs/Web/API/File/File#Parameters

new File([blob], "filename.json", {type: "text/json;charset=utf-8"});