Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://eu-west-1.amazonaws.com/duk-assets-uat/. (Reason: CORS request did not succeed).

[LimeBlast]

I've inherited a project from another dev which uses this gem. It used to work fine, but we've recently updated Rails from 4.2 to 5.0 (in an effort to take it all the way to 5.2), and it's stopped working.

The error we get when trying to use the form is:

Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://eu-west-1.amazonaws.com/duk-assets-uat/. (Reason: CORS request did not succeed).[Learn More]

We've checked the CORS setting on the bucket, and they're correct so far as we can tell:

<?xml version="1.0" encoding="UTF-8"?>
<CORSConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01/">
<CORSRule>
    <AllowedOrigin>http://clapboard-uat.herokuapp.com</AllowedOrigin>
    <AllowedOrigin>https://clapboard-uat.herokuapp.com</AllowedOrigin>
    <AllowedMethod>GET</AllowedMethod>
    <AllowedMethod>HEAD</AllowedMethod>
    <AllowedMethod>POST</AllowedMethod>
    <AllowedMethod>PUT</AllowedMethod>
    <MaxAgeSeconds>3000</MaxAgeSeconds>
    <AllowedHeader>*</AllowedHeader>
</CORSRule>
</CORSConfiguration>

My config looks like this:

S3DirectUpload.config do |c|
  c.access_key_id     = 'MY_ACCESS_KEY'
  c.secret_access_key = 'MY_SECRET_ACCESS_KEY'
  c.bucket            = 'duk-assets-uat'
  c.region            = 'eu-west-1'
end

So I'm all out of ideas. Can anyone help? Thanks.

[LimeBlast]

I think I've fixed the issue, I added the following to the config block:

c.url               = "https://#{c.bucket}.s3.amazonaws.com/"