This is likely because of new defaults in QuantumATK-2018.06. Your scripts were save with 'Minimal' option in 2016.4, i.e., you did not use 'Show defaults' when saving the script. In 2017 and 2018, the default basis sets are different (more accurate, but more expensive at the same time) from that of 2016 version. Also, for example, temperature broadening for the Fermi-Dirac distribution is now set to 1000 K instead of 300 K.