When I upload images to the Media Library, they get 500 errors. A thumbnail image of the picture that got the error on upload appears in the media library, and I can attach the image to a page. However, my slider plugin can only display an older image that didn't get the 500 error. Some days some of the thumbnail images disappear from the media library and or a leave blank space on the page where the image was uploaded, without my having done anything, and reappear hours or days later. Once I even saw the WordPress dashboard sidebar icons appear where the thumbnail image belongs!
I've spent days combing the support forums, and I've tried just about everything suggested, including:
- trying another browser
- deactivating my only plugin
- activating the default theme "twenty-twelve"
- clearing browser cache and cookies
- re-installing 3.5.1
- adding define('CONCATENATE_SCRIPTS', false ); to the bottom of wp-config.php file (just before the require_once line),
- added define('SCRIPT_DEBUG', true); just before "That's all, stop editing! Happy blogging"
- I checked for ghosts of deleted plugins, and found that there were none.
None of the above helped at all.
I didn't bother manually reinstalling WordPress, since the automatic install had never had a hitch, I had no reason to suspect it was incomplete. I felt that if I'd try it manually, I was far more likely to have an incomplete installation than if I didn't try this.
Many support threads blame hosts for media library problems. I may have to switch hosts. If that is your conclusion, please let me know what a host is supposed to be doing to prevent this problem, so that I can interview potential hosts.