The issue was found and fixed with Automation.Engine 12.0.6 in Agent MVS. The Package is available for download at the Automic-Support-Zone (https://support.automic.com
Hotfix-Description: z/OS agent may crash with system completion code 0C4 during file transfer activation.
A problem has been fixed where the z/OS agent may crash with system completion code 0C4 in some cases. The encrypted password field is not initialized and decryption fails in case no login user is specified.
The fixes also provided in below version
Automation.Engine 11.2.8, Automation.Engine 12.0.6