This article is only for first time installation of MAMP and WordPress on OS X. I was planning to setup a multisite on my installed MAMP but apparently I encountered database error issues. I had no choice but do it from scratch. Here are the steps for a successful WordPress Multisite on your Mac.
- Launch Terminal.
- Type sudo pico /etc/hosts and hit return.
- Type your admin password then hit return. (characters are not visible)
- Use your arrow keyboard to get to the right line. Type 127.0.0.1 localhost.donalyza (you can change “donalyza” to another name)
- Once you are done, hit the CTRL-X keys, then save changes by hitting the Y to indicate yes.
- Download and Install MAMP.
- Download WordPress.
- Open Finder
- Go to /Users/[username]/Sites. Then drag the downloaded WordPress folder into the Sites folder.
- Open MAMP.
- Click Open Start Page button, (default browser will automatically will run).
- Under MYSQL click the link phpMyAdmin.
- In the field Create new database, type wpdb then click Create button.
- Go to Finder.
- go to path Sites>WordPress folder, open wp-config-sample.php file. There are several items here that we need to change.
- After /** The name of the database for WordPress */, change ‘database_name_here’ to ‘wpdb’.
- After /** MySQL database username */, change ‘username_here’ to’root’.
- After /** MySQL database password */, change ‘username_here’ to ‘root’.
- After /* That’s all, stop editing! Happy blogging. */, add define(‘WP_ALLOW_MULTISITE’, true);.
- Save as file to wp-config.php.
- Relaunch MAMP.
- Click Preferences > Ports tab then click Set to default Apache and MYSQL ports button.
- Click Preferences > Apache tab select the folder where you save the WordPress folder. eg. /Users/[username]/Sites/wordpress.
- Open Safari.
- Type http://localhost.donalyza
- Install WordPress.
- Under WordPress Dashboard, Go to Tools > Network. Select Sub-Directories (Sub-domain will not work on localhost).
- Follow the instructions in Enabling the Network provided by WordPress.
Everything should be up and running by now. If something is not right on the steps I provided feel free to let me know. Cheers!

Hey I tried to follow your tutorial, however I get stuck at step 8 (a). Specifically, it tells me “You cannot use port numbers such as :8888.”. I tried changing the default port numbers, and now my entire local website won’t show.
Any suggestions?
I ran into the same issue. It turns out that system’s Apache server was already running using the default Apache port (80), so when the MAMP Apache tried to start using the same port system Apache killed MAMP Apache. The solution is to shut down the system Apache via terminal. Here’s the command: “sudo apachectl stop”.
I hope this helps you with your problem. Also, make sure the disk location is correct. The tutorial puts the disk location other than the default location provided by MAMP.