Summer '25: Redirect legacy (non-enhanced) My Domain hostnames update

As a workaround, re-enable "Redirect legacy (non-enhanced) My Domain hostnames" in My Domains setup.

It is recommended to only do so as a temporary measure and ensure that end users and stakeholders are informed that the affected URLs will no longer be supported or work properly after the Spring '26 major release.

For Chat use one of the following workarounds in conjunction with enabling "Redirect legacy (non-enhanced) My Domain hostnames":

• • Enable "Enable content delivery network (CDN) for Lightning Component Framework" via Setup | Session Settings. See Enable the Lightning CDN to Load Applications Faster for considerations. When Lightning CDN is disabled Salesforce loads the aura_prod.js file from the site domain in the chat deployment written into the 3rd party site. The JS file is set to load requiring CORS but the legacy force.com domain performs a redirect to the new domain and does not set the CORS headers, causing the browser to block and not launch the chat.

OR

• • Update your chat deployment (on your site) to use the latest version available for your org. Alternatively, replace or update the deployment references to *.force.com site URLs to *.my.site.com URLs for your experience sites.