I'm stuck on a problem with uploading files.
When I try to upload an image with 1024px or more, WordPress displays an error: Error sending. Try later.
After reloading the media page, the thumb of the file appears, but without showing the image. Testing the url of the file, I found that it is uploaded to the server.
UPDATE
The problem is related to WPML plugin. But apparently still there a solution.
WP_DEBUG
totrue
inwp-config.php
and observe what you get.