Noticed that sometimes I got an ORA-12519 error when using the oracle_ctl.bat file which calls SQL*Loader to upload each dat file into its Oracle table.
When I ran the script line by line I got no problems. Seemed like SQL*Loader was a little to fast for Oracle XE. Found this on the forums
Intermittent ORA-12519 error on 10g XE
ALTER SYSTEM SET PROCESSES=150 SCOPE=SPFILE
and restarting the database, my oracle_ctl.bat file ran without issues.