COS – SD macOS Installation

Last Updated on June 25, 2026

COS – SD Software on macOS Devices

COS Version 10 for macOS

All supported versions of macOS may require additional manual steps due to security updates to the COS maintenance tool. If you are completing a fresh installation – not trying to update from version 9 to 10 – you should not need to complete the additional steps unless you receive an error. If you encounter an error in the maintenance tool, you must clear the local cache in order to update to Version 10 of the COS – SD software.

For more information, see Manually Updating COS – SD Software on macOS Devices.

Rosetta Software and COS – SD Software for macOS Devices

If you are testing using a macOS device that has an M1 chip, the Rosetta software must be installed on the device before you install the COS – SD software. If the Rosetta software is not installed, during the installation process you will be prompted to install it.

Keep the following items in mind if you need to install the Rosetta software on your Mac device.

  • Application (Intel) means that the app supports only Intel processors and needs Rosetta to work on any Mac device with Apple Silicon processors.
  • Application (Universal) means that the app supports both Apple Silicon processors and Intel processors and uses Apple Silicon processors by default.

Quick Tour: Installing COS – SD Software on macOS Devices

Important: To access COS, you must have the Test Setup – Central Office Services permission.

  1. To launch the wizard and start the installation on a Mac (macOS) device that meets the COS – SD system requirements, sign in to your state’s Portal site, or WIDA AMS for WIDA testing, select MY APPLICATIONS–General Information–Downloads, and click the Central Office Services (COS) Installer download icon for macOS to download the COS installer for Mac.
  2. After you have downloaded the file, double‑click on the file to open it, and double‑click the coinstaller application file to launch the wizard.
    • Note: You must be a Mac System Administrator to install the COS – SD software from this file.
  3. The Setup – Central Office window displays for the Central Office Installation Wizard.
  4. Click Continue.
  5. The Installation Folder window displays. You must indicate where to install the COS – SD software and where to store downloaded content.The default location for the COS – SD software is /Applications/CentralOffice and the default location for the COS – SD software to store downloaded content is /Applications/CentralOffice/content_fs.
    1. You can use the Browse button to select different locations. DRC recommends that you use the default location.
    2. When you are ready, click Continue.
  6. The Proxy Host window displays. This window allows you to specify a separate proxy server for the COS – SD. This step is optional.
    • If you are not planning to use a proxy server, leave the field blank and click Continue.
    • If you are planning to use a proxy server, enter the URL of the server in the Proxy Host field and click Continue.
  7. The Ready to Install window displays. The window indicates the amount of disk space the installation will require and the components that will be installed as part of the COS – SD software.
    Click Install to continue (or click Go Back or the red circle to exit the installation).
  8. After you enter your name and password and click Install Software, the installation begins.
  9. The Installing Central Office window displays, indicating the progress of the installation. Click Hide Details to hide the details of the installation process or Show Details to reveal them. Note: The installation process can take 5–10 minutes.
  10. The Configure Service Ports window displays. From this window you can specify the port to use for Content Hosting (labeled as the Base port). The COS application uses the base port to determine which ports to use for the Content Downloading, Relay, and Restricted Proxy services (labeled the Additional ports).
    • The ports are four consecutive numbers, but you need to enter only the base port number in the Base port field. After you specify the base port, COS automatically selects the next three consecutively numbered ports. COS requires four port numbers even if the device being configured will not use all of them. The default port values are 55222, 55223, 55224, and 55225. You may select alternative port numbers as long as four consecutive numbers are available. Make sure the ports you select are properly allowlisted (for more allowlisting information, see Network Requirements for Testing Computers in Volume I: Introduction  to Online Testing). DRC recommends using the default ports.
  11. After you select your ports, click Test to verify that the ports selected are available on the device.
    • If the Installer dialog box indicates that the ports are available, click OK and then click Continue.
    • If the Installer dialog box indicates that the ports are not available, select a different base port and repeat this step until you have ports that are available.
    • Important: The ports you select may be blocked at the time of testing despite being available during installation. At testing time, verify that these ports are available and are open on your COS – SD’s firewall. If the ports are blocked the Testing Device will encounter a Connection Error that will prevent it from being used for testing.
  12. The Completing the Central Office Wizard window displays.
    • Important: From the Completing the Central Office Wizard window, highlight, copy, and save the URL that is displayed. You can use it to resume the process at this point (if necessary) without reinstalling the COS – SD software.
  13. Click Finish in the Completing the Central Office Wizard window. To complete the process of configuring your COS – SD, see Creating the Initial COS Configuration.

Manually Updating COS – SD Software on macOS Devices

DRC COS – SD software updates automatically at regular intervals. If a COS – SD is turned off when DRC releases an update, the COS – SD will not receive the update until the next time it is turned on at night.

Perform the following steps if you need to manually update the COS – SD software on a macOS device.

Important: To update to version 10 of the COS – SD software, all supported versions of macOS must clear the Qt installer cache and update the components in the Maintenance Tool again.

  1. From the COS – SD, select Applications–Central Office–maintenancetool.
  2. Enter your macOS Administrator login information.
  3. On the Setup – Central Office screen, select Update components and click Continue.
  4. When the update process is complete, a message is displayed indicating the results of the update. Click Done.
  5. Clear the Qt Installer Cache by opening Terminal and running:
    1. cd $HOME/Library/Caches
      Note: Ensure the path is correct before moving to step B.
    2. sudo rm -rf qt-installer-framework
  6. Launch Maintenance Tool.
  7. Select Update Components.
  8. Follow the ensuing prompts.

Uninstalling COS – SD Software on macOS Devices

To uninstall the COS – SD software from a macOS device, perform the following steps.

  1. From the COS – SD, select Applications–Central Office–maintenancetool.
  2. Enter your macOS Administrator login information.
  3. On the Setup – Central Office screen, select Remove all components and click Continue.
  4. On the Ready to Uninstall screen, click Uninstall.
  5. If necessary, reenter your macOS Administrator login information. The process takes a few minutes.
  6. When the process is complete, click Done.