I'm having the same problem, but I'm absolutely 100% sure my server is accepting HTTP head requests. Here's where I looked up how to check:
https://developer.mozilla.org/en-US/docs/Web/HTTP/Range_requestsHere's my server:
$ curl -i --head
http://www.uncannyjapan.com/wp-content/uploads/2018/09/Episode-22_-Great-Screaming-and-Uninterrupted-Pain-More-Buddhist-Hells.mp3HTTP/1.1 200 OK
Server: nginx
Date: Tue, 04 Sep 2018 00:57:22 GMT
Content-Type: audio/mpeg
Content-Length: 11849817
Last-Modified: Mon, 03 Sep 2018 15:02:43 GMT
Connection: keep-alive
ETag: "5b8d4d13-b4d059"
X-Powered-By: EasyEngine 3.8.1
Accept-Ranges: bytes
I can send a request for a byte range:
$ curl
http://www.uncannyjapan.com/wp-content/uploads/2018/09/Episode-22_-Great-Screaming-and-Uninterrupted-Pain-More-Buddhist-Hells.mp3 -i -H "Range: bytes=0-1023"
HTTP/1.1 206 Partial Content
Server: nginx
Date: Tue, 04 Sep 2018 00:50:31 GMT
Content-Type: audio/mpeg
Content-Length: 1024
Last-Modified: Mon, 03 Sep 2018 15:02:43 GMT
Connection: keep-alive
ETag: "5b8d4d13-b4d059"
X-Powered-By: EasyEngine 3.8.1
Content-Range: bytes 0-1023/11849817
Here's what I got back from Apple Support. Also, no matter what they say there definitely IS a darned <itunes:image /> in the feed
http://www.uncannyjapan.com/feed/podcast/ AND the image is absolutely, positively, 3000x3000px.
<QUOTE>
Below, you will find the troubleshooting steps that Engineering took to isolate the issue, and in determining that there is an issue with where the image file is stored and there is no <itunes:image /> tag in feed.
1. Copied their feed verbatim to new location and retained the original source.
2. Validate in PCC
3. Validation error:
"Podcast artwork must be between 1400 x 1400 and 3000 x 3000 pixels, JPG or PNG, in RGB color space, and hosted on a server that allows HTTP head requests."
4. Inspect feed. Feed has no "<itunes:image />”’ tag, only "<image>”
5. Added iTunes image reference to feed "<itunes:image href="
http://www.uncannyjapan.com/wp-content/uploads/2016/11/Uncanny-Japan-iTunes-Logo-3000x3000.jpg”/>
6. Same error
7. Change reference to image in feed to "http://[new feed location]/Uncanny-Japan-iTunes-Logo-3000x3000.jpg
8. Moved image to new location
9. Validate again in PCC
10. Validates fine and ready to submit.
</QUOTE>
Whatever's problem with my server, for the life of me I can't figure it out. Other sites running on the same server have the same problem.
One strange thing though, when creating a episode post in Wordpress, when I click the button to validate the MP3 file's URL, I get this error:
The requested URL returned error code 404, file not found.
Test:
http://www.uncannyjapan.com/wp-content/uploads/2018/09/Episode-22_-Great-Screaming-and-Uninterrupted-Pain-More-Buddhist-Hells.mp3The URL is valid, I can't figure out the reason for the 404 error.