Import Logs with valid url 0 lines parsed, 0 lines recorded

I am trying to import logs. All I get is 0 lines parsed, 0 lines recorded, 0 records/sec (avg), 0 records/sec

This could be related to my other questions about reverse proxy. Does import.py trigger the apache access log ?
Can somebody explain where matomo keeps its error logs ?
Thanks
Paul

You can check there: