To downgrade the Galaxy Client from a preview (beta) version to the public version, first try to disable the preview version in Galaxy’s settings.

1. Click on the GOG.com logo in the top-left corner of the Galaxy Client
2. Choose „Settings”
3. Disable the „Public beta” checkbox in the GENERAL section of the settings

If the checkbox is not clickable, then unfortunately a reinstallation of the Galaxy Client is required. Please follow these instructions to reinstall Galaxy:

On Windows you can access the Programs and Features panels and remove the Galaxy Client from there.

Manually removing the config.json might be required:
C:\ProgramData\GOG.com\Galaxy\config.json

You can access the directory using the Run... window (WinKey+R key combination) and entering:
%programdata%\GOG.com\Galaxy

On Mac you will have to go to the Applications directory and move the GOG Galaxy.app to trash, you will have to also remove the contents of this directory:
/Users/Shared/GOG.com/Galaxy/Storage

You can open it using the "Go to Folder" command accessible with the Command+Shift+G key combination or selecting Go > Go to Folder from the Finder menu.

You will also need to remove this file:
/Users/Shared/GOG.com/Galaxy/config.json

Now please download the latest installer available on our website:
https://www.gog.com/galaxy
After the installation completes start the Galaxy Client. Importing games will be required, you can do this by clicking on the GOG icon in the top left corner and selecting "Scan and import folders".