I know this is probably a file permission issue, but I can't figure out why it's happening. (I'm more trying to understand what's going on rather than looking for a quick fix.)
Why would I be able to upload media, but not update or install plugins? My
wp-content folder and even
plugins folders look to have the correct permissions. Apache server runs under
www-data and that group has ownership of the folders and files.
drwxrwsr-x 6 www-data www-data 4096 Apr 2 21:40 wp-content drwxrwsr-x 3 www-data www-data 4096 Apr 2 21:15 plugins
Note: I did read Why would WordPress request FTP information when it can write to the file server? but I'm still not completely understanding what's going on.
Note2: This is on a VPS not shared.