1.
The log snippet you posted is incomplete. There should a more specific
License Error message:
Are you perhaps redirecting standard output, but not error output?
viewtopic.php?t=3067
2.
How are you installing the license for your automation user? What does the console output say when you are successfully installing the license for your automation user?
3.
This error means that you haven't installed your license yet. If you think you have, then you're missing something, because FileBot doesn't remember.
Most likely reasons:
* You have manually installed the license as User A, but then you're running as User B, who as a completely different user with different $HOME directory, is completely separate from User A.
* You are using a non-persistent $HOME directory, meaning that FileBot is running for the first time, each and every time, because all memory is wiped between runs.
* ...
(anything that makes the application data directory not be persistent)

You're using the SNAP package. I recommend using the
DEB package instead, just to make sure you're not tripping on SNAP confinement.