Finaly made it!
I add thus to Input:
codec => plain {
charset => "ISO-8859-1"
}
And used this commandline toi start for debug:
logstash --log.level debug -f aTestfile_path_3cols.conf
and found that entry in logstash logs:
[2019-01-18T22:18:09,404][DEBUG][logstash.instrument.periodicpoller.cgroup] One or more required cgroup files or directories not found: /proc/self/cgroup, /sys/fs/cgroup/cpuacct, /sys/fs/cgroup/cpu
Search the Forum and find this:
Yeah made my day when changed from \ to / in path!
Lesson learned ELK Stack is quite a bit hypersensitive based on whatever matter because in Filebeat I can still use \ instead of / ?
...time for beer... 
Regards