Media Library Uploads Suddenly Stopped Working

I have had no trouble offloading all mp3 and mp4 files to generic s3 at iDrive, until today. Now the progress bar shows the upload, but it never transfers it to the cloud and doesn’t show up in the Media Library, despite the files being in the uploads directory.
Running system tests shows a few errors relating to plugins, but other than that it can upload and delete from s3 without problems. Even when I disable all plugins besides Media Cloud I still cannot get any mp3 to upload to s3 from the media library.