Http error occurred for fielfield sources remote url

This means that the server encountered an unrecoverable error when saving the image. Since the server can't return anything, Drupal's AJAX system returns that rather unhelpful error. Does this problem occur with all images? Or just one (or some) in particular? The most common problem is the server running out of memory when dealing with large files (especially if this is an Image field). Checking your server logs would be the surest way of determining this problem, since that's the only place these errors are recorded.

Often times the PHP logs are stored in the the Apache logs if you have PHP running as an Apache extension. You can easily Google your question.

Ah, well that's simple enough. Your PHP installation is missing the cURL library: http://php.net/manual/en/book.curl.php.

Yes, php_info() will tell you if cURL is enabled or not.

For help installing PHP extensions, please use other resources. If you can get cURL to show up in php_info(), but it's not being used by FileField Sources, then I can help you further. But it sounds to me like you just need help getting cURL working on PHP. There should be plenty of references on the internet for such a task.

I'm having the same/similar problem. I'm getting filefield/ahah/article/field_main_image/0

I noticed when I click the "Transfer" it throws the error and the dialog comes up, but when I just paste the url for the image file and hit return to submit the form, the page loads, Drupal says I forgot the title, but the image loads when I scroll down and see the preview. Also on the page load, I get this text at the top of the page.

HTTP/1.1 200 OK
Date: Wed, 15 May 2013 14:37:20 GMT
Server: Apache/2.2.23 (Unix) mod_ssl/2.2.23 OpenSSL/0.9.8e-fips-rhel5 mod_auth_passthrough/2.1 mod_bwlimited/1.4 FrontPage/5.0.2.2635
Last-Modified: Sun, 09 Dec 2012 02:03:07 GMT
ETag: "6b04ab3-601b-4d061d98accc0"
Accept-Ranges: bytes
Content-Length: 24603
Cache-Control: max-age=1209600
Expires: Wed, 29 May 2013 14:37:20 GMT
Content-Type: image/png

If I type filefield/ahah/article/field_main_image/0 into my URL as http://www.whatsmadeinamerica.us/filefield/ahah/article/field_main_image/0
I get
{ "data": "\x3cdiv class=\"messages error\"\x3e\nAn unrecoverable error occurred. The uploaded file likely exceeded the maximum file size (30 MB) that this server supports.\x3c/div\x3e\n" }

The file I'm using is my website logo.

To view this, you can visit my devel site at http://dev.whatsmadeinamerica.us/node/add/usa-made-product and use the main image field.

I'm not sure what is causing it, but I'm going to be checking modules and server logs over the next few days as my time permits.

Found out that its the 1.8 module causing the problem.
On my live site, I have 1.8 installed and on my dev, I have 1.7. Everything else is the same.

Next I'm going to dig into the code and commits to see whats different.

From my digging, I found out this was an issue in 1.5 version, and a patch was already made.

http://drupal.org/node/1795160#comment-6664786

I applied the patch to 1.8, no fails and the remote transfer works.

So along the lines, it was removed?

I'm not sure how to attach a patch and test it.... but here's the patch from #13

duplicate of #1795160: An HTTP error 0 occurred when transferring remote files