Following documentation to connect to a OBIEE server one may see the error:
Data Service Database Error
Invalid data source definition: Invalid response. Ensure you are connecting to the correct OBIEE URL.
The issue happens when connecting to a 12C instance, and, when checking the "System Requirements" section in the Release Notes for Toad Data Point (TDP) version 4.3, in the "Business Intelligence Connections" list, the only one listed is:
*** Oracle Business Intelligence Enterprise Edition 11g