Media upload randomly fails after 4.2 update

I updated my site to 4.2. Everything was working great before the update. The auto update hung the first time so I disabled all of my plugins and tried again. This time it hung on copying files and corrupted the site. I did a manual upgrade and everything was working as expected until I tried to upload a jpeg.

Some jpeg’s upload without error. Seems like all PNG’s work and I can’t get a pattern down to which jpegs work and which fail (all different sizes, dimensions, etc. I just uploaded 3 successfully and tried to upload a 4th and it failed. The file makes it to the server and is found under the uploads folder but the various sizes are not present. If I perform a rebuild thumbnails it fails with this error (The resize request was abnormally terminated (ID 164). This is likely due to the image exceeding available memory or some other type of fatal error.). The image that failed was 230kb. I was able to upload a 5.4mb one right after successfully.

I tried to enable debug mode but it doesn’t appear to output messages in the admin panel. Any ideas?

Thanks!!