When attempting to install the repository on Oracle 12c via ca-tdm-db-installer.exe, sqlldr.exe will crash and the repository will fail to install. This is due to a known issue with the Oracle 12c client version 188.8.131.52.
Release: TDMTDD99000-3.6-Test Data Manager-for Test Data on Demand
Before applying the Oracle client patch, make sure the ORACLE_HOME variable is set properly on the command line:
Also make sure that that the PATH statement is set accordingly to ensure patching is successful: