Here is the procedure to properly migrate a WordPress Multisite.
Step 1 – Move Database and Files
The first step is to open your FTP client and upload the files from your computer to the server. Next, on your server set up your database and user, and use phpMyAdmin to import all the database tables.
If you visit your site now it won’t work, you’ve got some more work ahead of us before you’ll be greeted by a fully working multisite installation on our production server.
Step 2 – Modify wp-config.php and .htaccess
Now we need to modify wp-config.php and the .htaccess files to reflect the new location, database name, user and password. This should be quite straightforward. Be careful to replace any instance of the old URL with the new one.
Step 3 – Modify Database Tables
This is the step when most things can go wrong. You need to carefully modify the database to reflect the new location of your site.
Go to table wp_options
In this table, change the fields site_url and home.
Go to table wp_blogs
Replace the domain and path fields with the new values.
Go to table wp_site
Replace the domain and path fields with the new values.
Go to table wp_sitemeta
Change the site_url field
Searching and Replacing within each Subsite
At this point your site should be loading, however you still have potentially many references to the previous URL in each sub site’s tables. We need to change those through a search and replace procedure.
Hope this helps.