meta.error is an object instead of string in IE11

[gelim92]

Are you submitting a bug report or a feature request?

bug

What is the current behavior?

meta.error errors returned from field validators is an object instead of a string in IE11 browser. For example, if I returned "error!" in a field validator, meta.error is an object in the form of { 0: "e", 1: "r", 2: "r", 3: "o", 4: "r", 5: "!" } .

Also this only seems to happen on Fields which are a parent of child Fields

What is the expected behavior?

meta.error should be a string instead of an object

Sandbox Link

https://codesandbox.io/s/final-form-validation-error-ie11-lb9wc?file=/index.js

What's your environment?

Browser: Internet Explorer 11 version 11.0.9600.19596

"final-form": "4.18.6" "react-final-form": "6.3.3" "react": "16.12.0" "react-dom": "16.12.0",

[alexpchin]

I'm also seeing this with parent / child fields.

[pmomot]

it's not only IE, I get the same behavior in the latest chrome

[seunggs]

Still a problem - seeing this in Chrome as well

[gertdreyer]

Please retest with the latest version and see #1007 for the same behaviour on the Form validator.