While playing, the game shuts down without an error message. Afterwards 2 files are missing, and after updating\downloading them it repeats all over again. How do I solve this?

Make sure that you have both full administration access in your Windows user account when playing, and that CSN:Z is running from a Steam installation made by your own Windows user account. There may be issues with CSN:Z not being able to update or create necessary files when launching.

If you still encounter issues after attempting to troubleshoot, please submit a ticket.