NZE-28804: Data source cannot close.
What triggered the Error:
The data source, which could be either a file or a database), failed to close.What should we do to fix it:
Enable Oracle Net tracing to determine the exact error.
If this was not sufficient go over to:
Oracle Official Support Knowledge Center
Or maybe those geeks at: StackOverflow Board
Or maybe those geeks at: StackOverflow Board