During the last upgrade pass I was attempting to apply patches to the upgraded environment and ran into an unusual error when trying to build the change package within Change Assistant.
As it turns out when we build the image, we did not force it to always use the same IP address. So every time it starts the IP address has a tendency to change. As it turns out this can cause some problems with the configuration that was done before on previous passes. Depending on your setup you may find that the Oracle Database Listening will not work, which in turn makes it unavailable for the application server and process scheduler and the database is not listening to requests. So you will need to change the listening and tnsnames files, as well as the tnsnames file on the server where change assistant is running.
However, the error with building the change packages was caused because the mapped drive for the “pi_home” on the virtual image was mapped as a network drive using the IP address. Once the mapping was changed and the pi_home was available the change package error was eliminated.