Fix WordPress Multisite Image Lost in WordPress Upgrade

When upgrading some WordPress Network (Multisite), I noticed images on some sites completely disappeared.  You only get a broken image icon in place of where the image used to be.  This says you can’t actually access the image through the path, the URL address, to the image.

I checked that the images are still on my server.

Images on the server should be located in

/wp-content/blogs.dir/(blog number i.e. 1, 2, 3...)/files

Images were there.  All Good.

So the issue is the address, not the actual images.

Solution

WordPress Multisite Networks do some address rerouting through the .htaccess file in the directory where you have WordPress installed on your server.  You may remember having to edit the .htaccess file when first installing Multisite.  Apparently, in the upgrade the .htaccess file needs to be changed as well.  So

1. In WordPress Network Admin, go to Settings > Network Setup
2. Find the upgraded .htaccess code on that page, step #3. Follow the directions (as you did when first installing a WordPress Multisite Network).  It will ask you to edit your current .htaccess file by pasting in the new .htaccess code.

For me (BUT NOT NECESSARILY FOR YOU!! CHECK YOUR OWN INSTALLATION), this was the code.  Use this as a reference for what you want to look for:

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

# uploaded files
RewriteRule ^files/(.+) wp-includes/ms-files.php?file=$1 [L]

RewriteCond %{REQUEST_FILENAME} -f [OR] RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L] RewriteRule . index.php [L]