“Error saving media attachment.” in Media Library

After uploading a normal jpg or png (anything) to the media library, we get the above error.

I’ve seen many posts on this topic and tried everything but still stuck.

I’m not the regular user, but I see dozens of other pictures have been uploaded, and suddenly we’re getting this error.

I checked the server, there is disk space, the permissions for Uploads and Images folders are writable (777) and I’ve confirmed that I can upload through the Plex control panel. I also tried deactivating all the plugins.

There are a couple things I’m also curious about, but I’m not sure if they are related:

1) One said to make sure “Always use HTTPS” is checked, but I do not have that option which is talked about here: http://en.support.wordpress.com/https/

2) If I go to wp-admin/network/settings.php I get the WordPress message “You do not have sufficient permissions to access this page,” even though I have a user with the Administrator role.

Is there another hidden user with greater permissions? Still not sure if that would help though, since everything was fine until recently.

Edit:

I found the cause, however I don’t know why it happened or how to prevent it from happening in the future. The user for the 2013 folder, and a subdirectory for this month only, was set to Apache instead of ourusername like all the other folders. I don’t know why this happened or how to prevent it from happening. I copied the folder and the user was by default set to ourusername which prevents the issue for now, but still wondering how to avoid this problem popping up again.