This action can not be undone because a store that uses the version 2.0 schema can not be downgraded to version 1.0. Clients ...

This action can not be undone because a store that uses the version 2.0 schema can not be downgraded to version 1.0.  Clients designed for the version 1.0 schema can not access stores that use the version 2.0 schema, however the version 2.0 schema is required for access to functionality that depend on the schema changes. Do you want to continue?