Just upgraded to v7.0.7 and the Oracle data sources already established had stopped working. During an attempt to create a new Oracle 12 data source and choose the Oracle 12 Thin Adapter, it fails with the error that the proper JDBC adapter must be installed.
Oracle drivers are missing in the install. Prior to this version, Oracle drivers came with the installation packed for the server.
Issue/Introduction
Just upgraded to v7.0.7 on our sandbox environment for testing and the Oracle data sources already established had stopped working
Resolution
Download the ojdbc7.jar file from Oracle
Place it (ojdbc7.jar) under conf/adapters/system/oracle_12c_thin_driver/
Restart the server
At this point, oracle 12c data sources can be created, tested and accessed.