An administrator is trying to deploy a change set from a newly upgraded sandbox source org with new features to a destination sandbox org on a…

Change sets cannot be deployed from an org on a newer Salesforce release to an org on a previous release. This is because the source org's metadata may contain features or updates unavailable in the destination org, leading to deployment failure. Refreshing the destination sandbox updates it to match the production org's current version and metadata. Since the source sandbox was upgraded as part of a major release, production is also on the new version. Refreshing aligns the destination sandbox version with the source, enabling a successful deployment.

A. Make the changes manually through the user interface in the source org. This is illogical; the changes are already in the source org. Manual changes would be needed in the destination org, which is inefficient.
B. Create a new sandbox on the new release version and deploy ;he change set to the new org. This does not solve the problem of deploying to the original destination org; it merely creates another sandbox on the new version.
C. Submit a ticket to Salesforce to update the source org to the latest release. The source org is already on the newer release, which is the cause of the incompatibility. The destination org is the one that needs updating.

- Salesforce Help. (2024). Change Sets. "Change Set Dependencies". This document notes that components in a change set can depend on features enabled in the source but not the destination.

- Salesforce Help. (2024). Considerations for Creating Sandboxes. "Sandbox Setup and Activation". This guide explains that refreshing a sandbox updates it to the version of the production org.

- Salesforce Release Notes. (Published seasonally). The release notes often contain sections on "Supported Browsers and API Versions" which implicitly confirm that metadata structures change between versions, making backward deployment impossible.