ETL termination codes

[Wim]

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.