<p>Defines the common version of all servers in a domain.
In a domain containing servers that are not all at the same
release version, this attribute is used to determine the
feature level that servers will assume.
The value must be less than or equal to the version of any
managed server in the domain.
If this value is not equal to the version of the release
version of the admin server, then the admin server will
not be allowed to make modifications to the configuration.
(Interface=weblogic.management.configuration.DomainMBean Attribute=getDomainVersion)