I've been using the Image Rotation Repair plugin to fix the orientation of images when uploading using the Media Uploader (some images taken on my camera phone are not rotated on upload, resulting in them displaying upside-down etc).
Although it worked pre WP 4.0 (possibly pre WP 3.9), uploading now fails and I get the error message: "An error occurred in the upload, please try again later".
Deactivation of the plugin resolves the upload error problem, but now the orientation of my images isn't right after uploading. Some need to be rotated.
I've also tried the Image Rotation Fixer plugin which results in the exact same upload error problem.
How can I fix the orientation of my images when uploading via the WordPress Media Uploader?