HTTP Error on Media Upload (WP 3.9)

I had the same problem, but it ended up being a different solution:

Uploaded a batch of images, but two errored out. Turns out they were the ones with an apostrophe ( ‘ ) in the file name. I deleted the apostrophes, and they uploaded without a problem.

I have a client that has this issue also. We’ve tested a lot of different things, but so far nothing is working. We did find out that me uploading (Im on a Mac) works just fine, I never have these errors, yet they always have the problem (on a PC) they tried it on a Mac and it worked just fine. We’re going to keep troubleshooting and if I figure anything else out I will post another message.

The plugin mentioned above fixed the issue for me. Thanks!

The solution edwahrer provided fixed my issue. Thanks alot!

I’ve had this issue for the past 24 hours after upgrading from 4.0.x to 4.1.x. Turns out it was a very simple fix so I thought I’d post back here in case it helps anyone else.

I was getting the same HTTP Error as discussed here and tried some of the suggestions here to no avail. However, upon investigating I discovered that the permissions on the file /wp-admin/async-upload.php were set incorrectly to 777. Upon changing the permissions to 644, the uploading worked again immediately.

I suspect this occurred because I was using FS_DIRECT in my wp-config with 777 permissions, and therefore when the file was updated it’s permissions were changed to an admittedly poor security level.

Thank you onebc, your solution worked for me.

@favethemes I just wanted to let you know we were getting this error in a VPS and used your code:

add_filter( 'wp_image_editors', 'change_graphic_lib' );

function change_graphic_lib($array) {
  return array( 'WP_Image_Editor_GD', 'WP_Image_Editor_Imagick' );
}

And it fixed the problem. Thank you!

for nginx users this may help.

edit: /etc/nginx/nginx.conf
change: client_max_body_size 4m;

edit: /etc/php-fpm.d/www.conf
change:
php_admin_value[upload_max_filesize] = 4M
php_admin_value[post_max_size] = 4M

restart services
# service nginx restart;
# service php-fpm restart;