When I try to upload an image, it appears to almost complete the process, and then fails. This is happening with even files under 10 KB, so it's not a large file problem, and my interaction with the rest of the site is working fine, so it's not an internet connection issue.
If I try via the "Upload New Media" page, using the multi-file uploader, the image's progress bar shows up and goes to 100% within a fraction of a second, and then stays at 100% rather than completing (it never shows up in the media library). If I switch to the browser uploader, when I select the file and click "Upload", it starts loading media-new.php, thinks about it for approximately 5 seconds, and then the page loading "completes" with nothing but a blank white screen.
If I click the "Add Media" button when editing a post, and then choose and upload a file, the progress bar fills up almost instantaneously, and then sits at a full progress bar for about 15 seconds, after which it gives an error: "An error occurred in the upload. Please try again later."
This has been a sporadically recurring problem, but in the past few days I haven't been able to get virtually anything at all through. A 7 kb PNG worked, but a JPG of the same size did not. It fails reliably in the evening, but sometimes works mid-day and often works late at night, which makes me think it's a load issue on the server end.
This is really hampering our blog usage.
The blog I need help with is royalcanterlotlibrary.net.