Fixing broken media URLs after moving to WordPress Multisite

Solution:

This should work for you.:

RewriteEngine On
RewriteCond %{REQUEST_URI} !^/wp-content/uploads/sites/2/
RewriteRule ^wp-content/uploads/(.*) /wp-content/uploads/sites/2/$1? [R,L]

If the url doesn’t contain wp-content/uploads/sites/2/ then it will add the sites/2/ to the url