What happens to my sandboxes after a release update or upgrade?

It depends on whether you published your sandbox before the release update was applied to the environment, or the environment was upgraded.

• If yes, your configurations will remain untouched.

• If not, you will lose the configurations you made in that sandbox. Also, you can no longer publish it. So, before the release update or upgrade happens, you should always publish or delete your sandboxes. If you're not done yet with your work in the sandbox, create a new sandbox in the updated or upgrade environment and make your changes there.