Yes, I am able to access them now. Thank you

Thank you, I hope so too. I’d like to plug those holes before anyone takes advantage of them

Yes, I am sure. I have three sites on my multisite network and I know which one is the main one and what’s the network admin dashboard.

The admin dashboard shows no menu for this plugin

I’ve been running my own site since 2003 and working with web admin and design for 15 years

.htaccess File Operations
wp-config.php File Operations
User Registration Settings
Registration Captcha Settings
Block Spambot Comments

Disabling plugins was the first thing I tried. I hardly suspect one of the best and most popular paid themes around is the culprit. Divi has gone to great lengths to make sure it doesn’t mess with other things.

The codex gives the following for a multisite .htaccess post WordPress 3.5:
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ – [L]

# add a trailing slash to /wp-admin
RewriteRule ^wp-admin$ wp-admin/ [R=301,L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ – [L]
RewriteRule ^(wp-(content|admin|includes).*) $1 [L]
RewriteRule ^(.*\.php)$ wp/$1 [L]
RewriteRule . index.php [L]

/wp-admin/network/setup.php says:

RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ – [L]

# uploaded files
RewriteRule ^([_0-9a-zA-Z-]+/)?files/(.+) wp-includes/ms-files.php?file=$2 [L]

# add a trailing slash to /wp-admin
RewriteRule ^([_0-9a-zA-Z-]+/)?wp-admin$ $1wp-admin/ [R=301,L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ – [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(wp-(content|admin|includes).*) $2 [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(.*\.php)$ $2 [L]
RewriteRule . index.php [L]

That last one actually worked, so now my images are back

I have already done that. Upload has worked well for many years.