Media Upload HTTP Error for Some Files

I am having an issue uploading some file to the media library on my site.

WordPress 4.3.1 running Twenty Fifteen theme.
All Plugins are disabled

php.ini:
max_execution_time = 30
memory_limit = 256M
upload_max_filesize = 200M
post_max_size = 200M

Tried:
Different Themes
https://github.com/getsource/default-to-gd

Added the following to .htaccess
<IfModule mod_security.c>
SecFilterEngine Off
SecFilterScanPOST Off
</IfModule>

Nothing so far fixed the issue.

Seems like any file less than 120KB uploads just fine. Anything larger gets the HTTP Error.

What am I missing?