There is a utility in the install folder for Notes (the same folder as notes.exe and nlnotes.exe) called ndctest.exe. I don’t know how your connection is configured. If it is on the server, then you need access to the server so you can run it from there to test the connection. It is odd that you intermittently get the errors. If you can log on to Oracle using SQL-Plus from the computer that is configured for oracle, and you can connect using ndctest.exe, you should be able to in Notes.