I am using WordPress 3.4.1, and until yesterday everything was working fine. Today, I tried to upload an image using both the browser uploader and the multi-file uploader, and after the progress bar reached 100% it just got stuck on "Crunching". The name of the file also disappears, and when I inspect the Network section it says that the async-upload.php file fails with a 500 Internal Server error.
Everything was working fine yesterday, with my same plugins and settings. I tried deactivating all my plugins, and it still appears to be broken. Can anyone give me some advice on how to get it working again? Uploading thumbnail images through FTP is no fun.
Thank you very much for all your help.