Undefined index: domain in /lib/W3/AdminActions/CdnActionsAdmin.php on line 380`

Hi,

I was trying to set up S3 as CDN. When I clicked Test S3 Upload it didn’t work because the server response was:

Notice: Undefined index: domain in /public_html/wp-content/plugins/w3-total-cache/lib/W3/AdminActions/CdnActionsAdmin.php on line 380
{"result":false,"error":"Error: Unable to list buckets (S3::listBuckets(): [AccessDenied] Access Denied)."}

https://wordpress.org/plugins/w3-total-cache/