Well, there's this, but it doesn't seem very helpful: Error:"OCI.dll not found" When Connecting to an Oracle Data Source | Tableau Software
Are you using a 64 bit version of Tableau? If so, make sure you've installed a 64 bit version of the Oracle drivers. (and vice versa if you're using 32 bit).
If that's note the case, then can you provide more detail on the error message? Does it say anything else other than OCI Not found?
Yes, I downloaded 64 bit and 32 bit drivers as a sanity check. I have not experienced this issue with any other DB. No it does not the logs seem to suggest that it cannot pick up the .dll files.
I've seen similar reports (here on the forums) lately and I'm just not sure of the cause. You may want to contact Tableau Support.
Yes will do. Thanks!