It looks like you unfortunately found a bug in ATK 2017: You did the restart in exactly the way prescribed in the tutorial, and it does not work. Please try this approach instead, which should avoid the error:
 
old_configuration = nlread("Ni100-InAs100_InTerm_1e19_dev_rlx2_MGGA_checkpoint.hdf5")[0]
configuration = nlread("Ni100-InAs100_InTerm_1e19_dev_rlx2_MGGA_checkpoint.hdf5")[0]
configuration.setCalculator(old_configuration.calculator(), initial_state=old_configuration)
configuration.update()
nlsave("Ni100-InAs100_InTerm_1e19_dev_rlx2_MGGA.hdf5", configuration)