Loading data into Oracle requires installation of the Oracle Data Provider for .NET, Managed Driver.

http://www.oracle.com/technetwork/database/windows/downloads/index-090165.html

ATTENTION: Only Oracle data provider version 4.122.1.0 (ODAC 12.2.0.1.0) is supported by Xtract Universal.

You should follow the instructions to install the 64-bit driver.
As an alternative to the managed driver the complete ODAC or the complete Oracle DB Client can be installed. Please make sure to select the ODP.NET component.

xu-oracle-odp-net-managed-driver