The new v9.4.0 OutputControl:Files object allows the user to disable the eplusout.end file. Both EP-Launch and EP-Launch3 assume that the simulation has crashed if there is no eplusout.end file and issues a message to that effect. So, EP-Launch needs to either mention this possibility in the warning message, or read the last line of the err output file to determine is there was a crash (eplusout.err is not optional, it is always produced).
The new v9.4.0 OutputControl:Files object allows the user to disable the eplusout.end file. Both EP-Launch and EP-Launch3 assume that the simulation has crashed if there is no eplusout.end file and issues a message to that effect. So, EP-Launch needs to either mention this possibility in the warning message, or read the last line of the err output file to determine is there was a crash (eplusout.err is not optional, it is always produced).
See discussion in https://github.com/NREL/EnergyPlus/pull/8250 .