[Jennifer2010]

mod_security - Not installed
suhosin - Not installed (using suexec)
A module of selinux - Not installed
Anti(malware/virus) scanners - Not installed
reverse proxies - We're using NGINX?
bad upload configuration - Not sure what this correlates to.

If you disable the flash uploader, to use the ajax one instead, does it work? Yes/No
One image at a time works. Multiple files selected results in the images not being inserted into the post. (one image at a time does not work on flash uploader)

If you disable the asset manager for the legacy uploader, Does it work? Yes/No
One image at a time works. Multiple files selected results in the images not being inserted into the post.

For example, I upload two different images one at a time and it works. If I select both of them and try to insert them, they fail and neither are inserted.

Does the AdminCP > Maintenance > Diagnostics > Upload File test work? Yes/No
Yes

file_uploads: On
open_basedir: None
safe_mode: Off
upload_tmp_dir: /tmp
upload_max_filesize: 100.00 MB

No errors occurred while opening the uploaded file for reading.

What should my image storage directory permissions be?

Thank you