Logstash keystore encoding error

That is telling you that it is trying to read the keystore as part of the configuration. In case this is not clear. If I configure a pipeline using

- pipeline.id: main
  path.config: "/bin/bash"

I get the error message "The following config files contains non-ascii characters but are not UTF-8 encoded "/bin/bash"]"

So when you run as a service path.config is getting set to /etc/logstash. How are you setting path.config when you run from the command line?