A *.car file created through the full server backup option contains more than the metadata of the objects created in the Studio client, and is therefore recommended for use when restoring an environment on a new installation of the same version rather than as a way to migrate library objects to an existing environment of another version. If you use such exports/imports between different environments, you must ensure that the environments are on the same version to avoid risks for instability issues on the target environment. 

An example of an error you may when trying to start the Studio client follows.

com.compositesw.client.CaRuntimeException: java.io.IOException: com.compositesw.cdms.datasource.UnknownDataSource cannot be cast to com.compositesw.cdms.ds.virtual.IVirtualWsdlDataSource