Looks like java-installer automatically updated you to JDK 19.0.2 and FileBot 4.9.6 happens to not be forwards-compatible with that. I've updated the java-installer deployment descriptor to JDK 17.0.6 for the time being. That should work. You can force a down-upgrade by uninstalling java-installer ...

I have removed filebot, filebot-node and JAVA-installer and reinstall them to other disk of Synology NAS (latest DSM 7.1.1-42962 Update 1).
Now I get the next.

filebot -script 'fn:amc' /volume2/Download --output '/volume2/Фильмы' --action duplicate -non-strict --order Airdate --conflict auto ...

Ok, thanks.

In test mode on two files one of them already exists:

filebot -script 'fn:amc' /volume2/Download --output /volume2 --action TEST --order Airdate --conflict override --lang en --def 'skipExtract=y' 'seriesFormat={def N = n.replaceTrailingBrackets().colon('\'' -'\'').slash('\'' - '\'').upperInitial ...

Thanks. Yes, it works but in wrong order. I should reorder folders in [] (in not obvious order).
I found that this construction is better:
{def N = plex[1].upperInitial().sortName(); ((output / 'first' / N).exists() ? 'first' : …) / N}

And during the tests I found that even if in filebot-node ...

Is it possible to refer to "Output Folder" specified in FileBot-Node? Or I must use absolute path inside [.., .., ..].?
def N gives not the same I wrote initially. But this not a problem.
The expression don't works. It always give me first part (/path/1st/N above) but this folder not exists. In this ...

Sorry, I need only check existence of folders "path/first/N" and "path/second/N".
How to read this: a.diskSpace <=> b.diskSpace?
There is no need in checking disk space. We should select path ONLY on the fact of existence of the folders (in order):
if (N exists in first)
we select path/first/N
else ...

I have some quantity of folders for TV serials (ex. /path/first/, /path/second/, /path/third/).
And now I use:
seriesFormat={path/s3/{n.replaceTrailingBrackets().colon(" -").slash(" - ").upperInitial().replaceAll(/^The (.*)$/, '$1, The')}/{s}{e.pad(2)}. {t} ({airdate})

let N will be the name of ...