Slack dialog doesn't close after form submission

Question

I created a slack dialog/form to collect some information from users; The form renders just fine and I can fill out the form without a problem but it doesn\'t close after I

Answer 1

Sending a 200 OK is not enough.

It also has to be empty OR contain a list of input validation errors in the correct format as JSON. If your response contains any other text (e.g. a warning message) it will create this error.

As it says in the documentation:

When the submission is without exception, your app must respond with 200 OK with an empty body. This will complete the dialog.

Answer 2

I had a similar problem (using golang and not JS). Responding with a 200 did not help, with or without body, but responding with a 204 code and no body fixed the problem.