Failed to enable unit: File cellular-keepalive.service: Invalid argument

hello,

I followed the how-to on a UC-8100A-ME box. On the line : "Enable systemd service: systemctl enable cellular-keepalive", I found an error: Failed to enable unit: File cellular-keepalive.service: Invalid argument

I do command with sudo.

Do you have some informations about this error?

[MoxaSystem]

Currently, we have no idea about the error. We have tested the scripts without problem. Could you share your steps (capture screen) of how you execute them.