Support » Fixing WordPress » Media Problems (Thumbnail Generation Hangs?)

  • Resolved pmkelly


    I had this problem a while back, and it seemed to get fixed with a WordPress version update. Now the problem has returned, apparently after upgrading to 3.5.1. When uploading an image to the Media Library, the process “hangs” and I eventually see an “HTTP Error”.

    It seems the image gets uploaded fine, as I can see it in the wp-content/uploads directory structure. But none of the thumbnail files appear. As an example, when I upload an image called “Red.jpg”, the image itself appears in wp-content/uploads/2013/03. But thumbnail files that are usually generated (e.g. “Red-300×200.jpg”) do not. And, as I mentioned, the progress bar in the media uploader page “hangs” for a while and eventually displays an “HTTP Error” message.

    Another side effect can be seen in the database. If I look in the “wp_postmeta” table, I can see an indication of this problem, although I do not fully understand the significance. For most images, if I look in the “wp_postmeta” table, I will see and entry for “_wp_attached_file” and “_wp_attachment_metadata”. For this new image having the error, though, I only see “wp_postmeta”. There is no entry for “_wp_attachment_metadata”.

    Anyone have any clue what may be going on here? I did all the standard troubleshooting things to no avail (disable plugins and themes). Completely stuck.

Viewing 4 replies - 1 through 4 (of 4 total)
  • esmi


    Forum Moderator

    That sounds suspiciously like a server mod_security issue. Have you spoken to your hosts about it? In the meantime, try checking your site’s error logs for a more specific error message. Your host should be able to help you in accessing your site’s error logs.

    Will give it a try. Thanks!

    Took forever to get hold of the log files, but have access to them now. The offending error in the log — or at least one of them — appears to be:

    php5: UnableToConcatenateString `\x10\xb4\xaa\x03′ @ fatal/string.c/ConcatenateString/443., referer:

    Any thoughts?

    Not sure this was an “ideal” resolution, but here’s what happened in case it is useful for anyone.

    I moved to another hosting company.

    Something of a last-resort option, and I am not putting it out there as a suggestion for others to follow. I never did figure out what the underlying issue was. But after a week of back-and-forth with my original host’s technical support, they basically told me “it’s a problem with your wordpress installation and not anything to do with our servers”.

    I moved the exact same files to another provider, imported the database, and the problem is no longer apparent.

    Again, not suggesting others take this path, since I never did determine the real cause for the issue.

Viewing 4 replies - 1 through 4 (of 4 total)
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