OWB Error

I was trying to load a flat file into an external table in Oracle Warehouse Builder and I got a strange error. OWB validated both the flat file and the external table, it generated the script, I deployed it and the table was created ok too. However when I tried to do a select from the external table my sql session was terminated.
There was also no .log or .bad file produced which made the problem investigation even harder.

The flat file had 56 columns and at first I thought there may be some limit to the number of columns. The problem however turned out to be a mispelling with the date format. I had accidentally typed hh24:mis:ss format for a date field.

Bit disappointed that OWB did not catch this out in the validation.