At first, I wanted to thank you a lot. You really saved my day, I was struggling with exactly same problem for few days now.
Also same fix worked for me (disabling IM within WP). How did you disable it and forced WP to use GD? Is there maybe some constant to add in wp-config to do that? Since it’s quite new feature, I haven’t found much in documentation. I rewrote the IM availability in class-wp-image-editor-imagick, so it would always result in false, but this is not really clean solution and it will work till next update…
If your host will update the library and you will test it again, please let us know, if it worked. I also need something to persuade my host to update those libraries.
