ETL termination codes

We are using Genesys 6.5 and we are having problems with our reporting. There are gaps in the reports so it looks like the aggregation is not successful. I am checking the ETL logs and I see messages that I did not see when there were no problems:

Process [ETL_Trans_Only] has terminated with exit code 254

and also:

Process [ETL_Trans_Only] has terminated with exit code 145

does anyone know what these exit codes mean? I checked the Genesys standard documentation and their support website and could not find anything.