# Instructions for Upgrading to Crafter CMS 3.0.19 from a previous 3.0.x version¶

After upgrading your Crafter CMS install, you will need to update the site-config configuration file in your existing site.

If you were using the Site Configuration file located in config/studio/site-config.xml to configure your preview server: <previewServer>http://localhost:3000</previewServer>

You will need to remove it and instead configure it in the Environment Configuration file located in: config/studio/environment-config/environment.xml <preview-server-url>http://localhost:3000</preview-server-url>

You can access the configuration files by following the locations listed above, or, you can use Studio. To change the configuration in Studio, open the Sidebar then click on Site Config. Click on Configuration next and select Environment Configuration or Site Configuration from the dropdown box.