Support » Fixing WordPress » Media upload error of jpeg slides taken from powerpoint

  • On a previous thread, I was told that the intermittent 500 errors I got on upload and the other queer things that happened in my Media library – including mysteriously disappearing and reappearing thumbnail images, and appearance of the administration sidebar a second time in the Media Library screen – are a hosting problem. I convinced my host that the problem is real by sending them screenprints and error logs, but their level three technicians were unable to duplicate the errors, so they couldn’t see whether their attempt to fix it had worked, until I updated the support ticket to tell them that it hadn’t.

    I’d done EVERYTHING in the support forum troubleshooting guide. As a last resort, I backed up my site, deleted the folder called “wordpress”, and uninstalled WordPress in the control panel. Then I installed version 3.4.2 from the control panel, because I didn’t recall having had this problem before the upgrade to 3.5. This did not help. The same errors occurred on 3.4.2, so I deleted and uninstalled again, and did a fresh install of 3.5.1, all from the control panel. Note: Doing this through the control panel was more thorough than simply re-installing from the WordPress administration dashboard, as I had already done several times before. I had tried repeatedly and failed to upload WordPress using FileZilla, so this was the closest I could get to a manual upload.

    I turned off all comments, deleted the sample page, the sample post, and all the plugins that came with the installation. I still got errors on upload, but my host could not duplicate them.

    I just discovered a pattern that had been hard to see before the clean install. The only files to get errors on upload today are the jpeg pictures that I’d made by saving a powerpoint presentation as a folder of individual slides, using a computer with Windows 7 Starter that is not equipped to edit powerpoint files, and only has a powerpoint viewer that I got as a free download. A minute or two after the media upload screen reaches 100%, an HTTP error message displays on the top of the screen; using the browser’s javascript console, I see on the lower half of the screen that it is a 500 error.

    Looking at the uploaded files in my control panel’s File Manager, I see that the files that uploaded without error all had multiple copies in various sizes created by WordPress. (I had read that this is the second stage of an image upload.) The images that got a 500 error only have the original in the uploads folder. This proves that the upload failed in its second stage.

    The uploads folder lists file sizes, and I noticed that the slides that got the errors are much bigger than the pictures I’d uploaded successfully. I wanted to see if I could make them smaller, figuring this might help. I did this on the computer where I’d originally created the powerpoint presentation, and saved the pptx file as jpeg, making a new folder of slides. Each of the new slides was less than a tenth of the KB of the corresponding old slides.

    The newer, smaller slides uploaded without error. Even the largest of the first set of slides was only 1007 KB, well within the 20 MB (=20,000 KB) limit for file upload, so the size alone didn’t seem to be an adequate explanation for the failure of the larger ones to upload. I then tried and succeeded uploading a much bigger (4 MB = 4000 KB) jpeg photo without error, which I saw in file manager has been reproduced in various sizes, proof that the upload of that file completed its second stage, and that size is not the reason why these slides didn’t upload.

    Visually, the first set of slides looks perfect, but evidently they were badly corrupted by being produced in a computer that didn’t support powerpoint editing, badly enough to prevent WordPress from making copies of them in various sizes.

    While thirteen evidently corrupted slides sat in my uploads folder (in their original form only), my Media Library had some really weird effects. The WordPress administration sidebar sometimes appeared a second time in the middle of the Media Library screen. The thumbnail images of these slides, as well as of all the other pictures I’d uploaded, would mysteriously disappear, some or all of them at a time, reappearing days or hours later, for no apparent reason. While a file’s thumbnail was missing, it was impossible to view it in the edit mode, to attach it to a page or post, or to see it in a page or post. Although upload of the corrupted slides almost always failed (and once even crashed my website), other files sometimes failed as well, making the cause of the problem very hard to diagnose.

    Could all of these weird effects be caused by the evidently corrupted slides sitting in the upload folder, or is this truly a hosting problem? My host is clueless what caused these errors. My contract with them is about to expire. I have backed up my site to my local computer to do all this testing, and I’m going to have to rebuild it from scratch anyway. Please let me know if I’d be better off switching hosts, or if all of this is my fault for trying to save a powerpoint presentation as a folder of jpeg slides, using a computer that doesn’t support powerpoint editing.

Viewing 9 replies - 1 through 9 (of 9 total)
  • esmi


    Forum Moderator

    The issue may be in the images themselves. Do not use jpg files created by Powerpoint as they will not be optimised for web use. Create them using a graphic package such as

    1) Can I use this package on a computer that is not equipped for editing powerpoint?

    2) Once I download this package, can I run it without an internet connection?

    3) It makes sense to me that the 500 errors are caused by the images themselves. However, can the problem with these images also explain all the weird side effects with the thumbnails, the administration sidebar appearing twice in the Media Library, and the problems with files that didn’t get upload errors?



    Forum Moderator

    1. It can be installed in any Windows computer. I’ve used it on both Win 7 and XP.

    2. Yes. It’s completely standalone.

    3. We really need to tackle one problem at a time. There may be more than 1 issue on your site, so we have to rule out/change one thing at a time.

    I clicked that link and it looks like they have a lot of different things to download. The first one there is gimp-2.8.4-setup.exec. Right below it is a help file, gimp-help- .exec Are those what you meant, or should I click graphics in the sidebar?

    I started looking through the list of graphics programs on that site. One of them, Caesium Image compressor, is designed for making pictures more compact for use on the web. Is that what you meant? This evidently takes an ordinary photograph (i.e., that jpeg that I already converted from powerpoint) and compresses it. Or do you mean a program to convert directly from powerpoint to something I can upload? I did a search on that site for powerpoint, but nothing came up.

    Gimp’s set-up files were corrupted, also from second download. The earlier version’s set-up files were also corrupted. Caesium’s set-up didn’t even download although I tried three times.

    I did a search in the support forum for “image optimization codex” and found that there are plugins that optimize whenever you upload an image to your site. Should I try that route instead? If so, what features should I look for in an optimization plugin?

    I looked for a jpg or image optimization plugin that is 3.5.1 compatible, with high percentage of recent support forum posts resolved, and excellent reviews. After rejecting one that is only for Linux and another for requiring the images to be uploaded to another site, I was left with only one plugin that fit the bill, EWWW Image Optimizer. The only downside in the reviews is that it is difficult to install, since it requires downloading programs from, the same site you mentioned. The download didn’t work, so I’m back to square one.

    Should I forget about optomizing and just put my website back together? Or maybe switch hosts?

    This plugin’s instructions say “EWWW Image Optimizer calls the optimization utilities directly (which may also allow us to offer more flexibility in the future). This is better suited to shared hosting situations where these utilities may already be installed. The programs we use (jpegtran, optipng, and gifsicle) generally have very minimal dependencies, so all you will need is a hosting account with shell access, and build utilities installed. You can then tell EWWW Image Optimizer where you compiled these utilities. I use Bluehost, which meets these requirements, and Dreamhost is another suitable alternative. There are likely others out there that I am not aware of.”

    Unfortunately, my host doesn’t have these optimization utilities already installed. I’ll have to check on “shell access” and “build utilities”.

    Thank you so much, Esmi. I’m using Gimp.

    1) Gimp’s “Export to JPEG” screen is asks me whether I want to retain the thumbnail. When I don’t retain it, the image is a few less KB. Does WordPress use the thumbnail? If it does, I ought to retain the thumbnail, and if not, I ought to remove it. I couldn’t find anything about this in the support forums.

    2) Where is the URL information stored for Media items? I can’t find a table or directory in wp-content.

    Thanks for making me aware of the importance of optimizing media. I also downloaded an audio optimizing utility from

    Looking through the support forums for more information on image optimization, I found that one moderator wrote in an informational post about media upload problems that it is important to reduce the size of the image in PIXELS as well as in KB:

    “Try a smaller image, in pixels. Filesize is largely irrelevant, it’s the width and height of the image that matters. Smaller images require less RAM. Although WordPress does attempt to tell PHP to allow it enough RAM, not all server configurations allow this and so PHP may not be set to have enough memory to work with larger images. Resize the images to web-sizes before uploading them.”

    I found that my slides had overly large pixel sizes. Presumably, the people who designed PowerPoint choose this size because it is appropriate for display to a group of people on a big wall screen. Obviously, a computer screen has far fewer pixels, so the first step in optimization of slides from PowerPoint for online use, is to reduce the pixel size to what I want to display on my site. As an added bonus, I found that this reduces the KB as well. After that, I’ll optimize them further with Gimp, upload it all and see if the problems disappeared.

Viewing 9 replies - 1 through 9 (of 9 total)
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