Why can't I add tools to my sandbox?

It might be because of one or more of these reasons.

• Your mainline metadata has changes from other published sandboxes. You must refresh your sandbox and then add tools to it.

• You just had a release update or upgrade, and you can no longer add tools to any of the sandboxes that were available before the update or upgrade. In the future, add tools to your sandboxes before the release updates or upgrades happen.

• A migration set was just applied to your environment, and now you can't add any tools to sandboxes that already have Application Composer. In the future, add tools to sandboxes before applying any migration sets.